Citrus College - NASA SL Criticla Design Review

Critical Design Review Report

NASA Student Launch

Mini-MAV Competition

2014-15

1000 W. Foothill Blvd.

Glendora, CA 91741

Project Λscension

Jan 15, 2015

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ContentsGeneral Information.........................................................................................................................8

School Information......................................................................................................................8

Adult Educators...........................................................................................................................8

Safety Officer...............................................................................................................................8

Student Team Leader...................................................................................................................8

Team Members and Proposed Duties..........................................................................................8

NAR/ TRA Sections....................................................................................................................9

I. Summary of CDR Report...........................................................................................................10

Team Summary..........................................................................................................................10

Launch Vehicle Summary.........................................................................................................10

AGSE/ Payload Summary.........................................................................................................10

II. Changes made since PDR.........................................................................................................11

Changes to Vehicle Criteria.......................................................................................................11

Changes to AGSE/ Payload Criteria..........................................................................................11

Changes to Project Plan.............................................................................................................11

PDR Feedback...........................................................................................................................11

III. Vehicle Criteria........................................................................................................................13

Design and Verification of Launch Vehicle..............................................................................13

Flight Reliability and Confidence..............................................................................................13

Mission Statement.................................................................................................................13

Requirements and Mission Success Criteria..........................................................................13

Major Milestone Schedule.....................................................................................................14

Design Review.......................................................................................................................15

System Level Functional Requirements................................................................................25

Workmanship as it Relates to Mission Success.....................................................................32

Additional Planned Component, Functional, and Static Testing...........................................33

Manufacturing/ Assembly Status and Plans..........................................................................34

Design Integrity.....................................................................................................................37

Safety and Failure Analysis...................................................................................................41

Subscale Flight Results..............................................................................................................43

Flight Data.............................................................................................................................43

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Predicted and Actual Flight Data Discussion........................................................................44

Impacts on Full-Scale Launch Vehicle..................................................................................46

Recovery Subsystem..................................................................................................................46

Parachute, Harnesses, Bulkheads, and Attachment Hardware..............................................47

Electrical Components...........................................................................................................49

Drawings, Sketches, Block Diagrams, and Electrical Schematics........................................49

Kinetic Energy at Significant Phases of the Mission.............................................................50

Test Results............................................................................................................................50

Safety and Failure Analysis...................................................................................................51

Mission Performance Predictions..............................................................................................52

Mission Performance Criteria................................................................................................52

Flight Profile Simulations......................................................................................................52

Scale Modeling Results.........................................................................................................55

Stability Margin.....................................................................................................................55

AGSE/ Payload Integration.......................................................................................................56

Ease of Integration.....................................................................................................................58

Integration Plan......................................................................................................................58

Compatibility of Elements.....................................................................................................60

Simplicity of Integration Procedure.......................................................................................62

Changes to AGSE/ Payload...................................................................................................63

Launch Concerns and Operation Procedures.............................................................................63

Final Assembly and Launch Procedures................................................................................63

Safety and Environment (Vehicle and AGSE/ Payload)...........................................................71

Updated Preliminary Analysis of Failure Modes..................................................................71

Updated Listing of Personnel Hazards..................................................................................75

Environmental Concerns.......................................................................................................78

IV. AGSE/ Payload Criteria..........................................................................................................80

Testing and Design of AGSE/ Payload Equipment...................................................................80

Design Review.......................................................................................................................80

Planned Component, Functional, and Static Testing...........................................................139

Manufacturing/ Assembly Status and Plans........................................................................142

Integration Plan....................................................................................................................145

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Precision of Instrumentation and Repeatability of Measurement........................................149

AGSE/ Payload electronics..................................................................................................150

Safety and Failure Analysis.................................................................................................158

AGSE/ Payload Concept Features and Definition...................................................................159

Creativity and Originality....................................................................................................159

Uniqueness or Significance.................................................................................................159

Suitable Level of Challenge.................................................................................................159

Science Value..........................................................................................................................159

AGSE/ Payload Objectives and Success Criteria................................................................159

V. Project Plan.............................................................................................................................161

Status of Activities and Schedule............................................................................................161

Budget Plan..........................................................................................................................161

Funding Plan........................................................................................................................164

Timeline...............................................................................................................................165

Educational Engagement.....................................................................................................167

VI. Conclusion.............................................................................................................................170

Appendix A: Citrus College Profile...........................................................................................171

Figure 1: Organizational flow chart.................................................................................................9Figure 2: Rocket exploded view....................................................................................................15Figure 3: Side and bottom view of the rocket................................................................................16Figure 4: Rocket booster section...................................................................................................17Figure 5: Rocket middle section....................................................................................................18Figure 6: Main parachute piston....................................................................................................19Figure 7: Payload containment bay and nose cone exploded view...............................................20Figure 8: Rendering of the payload containment device...............................................................21Figure 9: Description of nose cone and payload containment system...........................................22Figure 10: Piston Ejection Ground Test.......................................................................................23Figure 11: Aerotech K1275R Thrust Curve.................................................................................25Figure 12: AeroPack Retainer.......................................................................................................40Figure 13: RockSim Design of the 2/3 Subscale Vehicle.............................................................43Figure 14: The Rocket Owls with the Subscale Launch Vehicle.................................................45Figure 15: The Subscale Altimeter Bay with Redundant RRC2+ Altimeters..............................45Figure 16: The Subscale Vehicle under Two Parachutes.............................................................46Figure 17: Recovery Deployment.................................................................................................47Figure 18: Electrical schematics for the main recovery system....................................................49Figure 19: Electrical schematics for the payload recovery system................................................50

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Figure 20: Simulated Drag, Velocity, and Altitude......................................................................52Figure 21: Flight profile simulations.............................................................................................53Figure 22: Stability Diagram........................................................................................................55Figure 23: Description of payload containment and nose cone section........................................56Figure 24: Rendering of the Payload Containment Device...........................................................57Figure 25: Dimensional drawing of the payload containment device...........................................58Figure 26: The integration of the payload containment device into the launch vehicle................60Figure 27: Side view and section view of the payload containment device..................................62Figure 28: AGSE Isometric System Overview..............................................................................82Figure 29: AGSE Exploded System Overview.............................................................................83Figure 30: AGSE System Master Switches...................................................................................84Figure 31: Body Overview............................................................................................................88Figure 32: Chassis Dimensions.....................................................................................................89Figure 33: Chassis Design.............................................................................................................90Figure 34: Chassis Dimensions.....................................................................................................91Figure 35: Chassis Lid Design.......................................................................................................92Figure 36: Chassis Lid Dimensions...............................................................................................93Figure 37: Rocker Bogie Overview...............................................................................................94Figure 38: Center Bogie Design....................................................................................................95Figure 39: Front Bogie Design......................................................................................................96Figure 40: Front Bogie Dimensions..............................................................................................97Figure 41: Rear Bogie Dimensions................................................................................................98Figure 42: Rear Bogie Design.......................................................................................................99Figure 43: Camera Mount Shaft Design......................................................................................100Figure 44: Camera Mount Shaft Dimensions..............................................................................101Figure 45: Camera Mount Shaft Base Design.............................................................................102Figure 46: Camera Mount Shaft Base Dimensions.....................................................................103Figure 47: Wheel Assembly Design Overview...........................................................................104Figure 48: Servo Bracket Design.................................................................................................105Figure 49: Servo Bracket Dimensions.........................................................................................106Figure 50: Servo Pivot Bracket Design.......................................................................................107Figure 51: Servo Pivot Bracket Dimensions...............................................................................108Figure 52: Motor Mount Design..................................................................................................109Figure 53: Motor Mount Dimensions..........................................................................................110Figure 54: Pivot Shaft Washer Dimensions.................................................................................111Figure 55: Pivot Shaft Washer Dimensions.................................................................................112Figure 56: Wheel Spindle Design................................................................................................113Figure 57: Wheel Spindle Dimensions........................................................................................114Figure 58: Wheel Hub Designs....................................................................................................115Figure 59: Wheel Hub Dimensions.............................................................................................116Figure 60: Wheel Design.............................................................................................................117Figure 61: Wheel Dimensions.....................................................................................................118Figure 62: Mouth of Chassis Prototype.......................................................................................123

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Figure 63: Fully assembled AL5D robotic arm...........................................................................124Figure 64: Elbow Servo (Left) and Base Servo (Right) Bracket Mounting................................124Figure 65: HS-422 Gripper (left) and Wrist Servo (right)...........................................................125Figure 66: Rocker Bogie Failure.................................................................................................127Figure 67: Pan/ Tilt servo test schematic.....................................................................................129Figure 68: Wiring Setup for Pan-Tilt Servo Test........................................................................130Figure 69: PixyMon Calibration and Testing..............................................................................131Figure 70: Overall AGSE Electrical Schematic..........................................................................150Figure 71: AGSE Overall Block Diagram...................................................................................151Figure 72: Pixy Camera Block Diagram.....................................................................................152Figure 73: Robotic Arm Block Diagram.....................................................................................152Figure 74: Allpower Power Bank................................................................................................153Figure 75: Single 4.2 Volt Battery Testing..................................................................................154Figure 76: Series Circuit Using Both Batteries...........................................................................155Figure 77: Master and Pause Switch Locations...........................................................................156Figure 78: Planned Budget Distribution......................................................................................163Figure 79: NASA Student Launch Timeline...............................................................................165Figure 80: AGSE and Rocket Construction Timeline.................................................................166Figure 81: Outreach Timeline......................................................................................................166

Table 1: Team Member Duties.......................................................................................................8Table 2: Major Milestone Schedule..............................................................................................14Table 3: Piston Ejection Test Results............................................................................................24Table 4: Final Motor Selection......................................................................................................24Table 5: Launch Vehicle Requirements and Verification............................................................26Table 6: Recovery Requirements and Verification......................................................................30Table 7: Remaining Manufacturing and Assembly Schedule.......................................................34Table 8: Vehicle Subsystem Parts and Manufacturing Processes................................................35Table 9: Vehicle Subsystem Parts and Manufacturing Processes................................................38Table 10: Vehicle Weight, Altitude, and Rail Velocity................................................................41Table 11: Vehicle Failure Modes..................................................................................................41Table 12: Propulsion Failure Modes..............................................................................................42Table 13: Recovery Subsystem Components...............................................................................47Table 14: Kinetic Energy of each Rocket Section........................................................................50Table 15: Recovery Failure Modes................................................................................................51Table 16: Drift from Launch Pad (all sections)............................................................................55Table 17: Internal Interfaces..........................................................................................................61Table 18: Vehicle Failure Modes..................................................................................................71Table 19: AGSE Failure Analysis.................................................................................................72Table 20: Propulsion Failure Modes..............................................................................................73Table 21: Recovery Failure Modes................................................................................................74Table 22: Tripoli minimum distance table.....................................................................................75Table 23: Tool Safety....................................................................................................................76

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Table 24: Environmental Hazards.................................................................................................78Table 25: Project Risk Quantitative Assessment...........................................................................79Table 26: Project Risk Qualitative Assessment.............................................................................79Table 27: AGSE Subsystem Overview..........................................................................................81Table 28: Body Subsystem Component Overview........................................................................85Table 29: Camera Subsystem Component Overview..................................................................119Table 30: Payload Retrieval Subsystem Component Overview..................................................121Table 31: Structural Capacity Summary for the Body Subsystem..............................................126Table 32: Test Summary for Body Components.........................................................................127Table 33: Test Summary for Camera Subsystem Components...................................................128Table 34: AGSE Requirement Verifications...............................................................................133Table 35: AGSE Requirements...................................................................................................136Table 36: Test Summary for Body Components.........................................................................139Table 37: Test Summary for Camera Subsystem Components...................................................140Table 38: Test Summary for Payload Retrieval Subsystem Components...................................141Table 39: Component Level Integration......................................................................................147Table 40: Camera Subsystem Instrumentation Performance.......................................................149Table 41: Payload Retrieval subsystem Instrumentation Performance.......................................149Table 42: Testing Plans for Safety Related AGSE Electronics...................................................157Table 43: AGSE Failure Analysis...............................................................................................158Table 44: Scientific Objectives & Success Criteria.....................................................................159Table 45: Budget..........................................................................................................................161Table 46: Funding Plan................................................................................................................164

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General Information

School Information

More information on Citrus College can be found in Appendix A

Adult Educators

Lucia Riderer Rick MaschekPhysics Faculty/ Team Advisor Director, Sugar Shot to Space/ Team [email protected] [email protected](626) 643-0014 (760) 953-0011

Safety Officer

Alex [email protected](626) 643-0014

Student Team Leader

[email protected](509) 592-3328

Team Members and Proposed Duties

The 2014-15 Citrus College NASA Student Launch team, the ‘Rocket Owls’, consists of five students, one faculty team advisor, and a team mentor. The student members’ proposed duties are listed in Table 1 below.

Table 1: Team Member Duties

Team Member Title Proposed Duties

Aaron Team LeaderOversight, coordination, and planning

Assistance with all team member duties Lead rocket design and construction

Alex Safety Officer Implementation of Safety Plan

Brian Robotics Specialist Lead AGSE design and construction

John Payload Specialist Oversight and coordination of payload acquisition, retention, and ejection systems

Joseph Outreach Officer Educational EngagementSocial Media, Website maintenance

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mailto:[email protected]



Figure 1: Organizational flow chart

NAR/ TRA Sections

For launch assistance, mentoring, and review, the Rocket Owls will associate with the Rocketry Organization of California (ROC) (NAR Section #538, Tripoli Prefecture #48) and the Mojave Desert Advanced Rocket Society (MDARS) (Tripoli Prefecture #37).

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I. Summary of CDR Report

Team Summary

Citrus College Rocket Owls

Mailing address: Team Mentor:Lucia Riderer Rick MaschekPhysics Department TRA #11388, Cert. Level 2Citrus College1000 W. Foothill Blvd.Glendora, CA 91741

Launch Vehicle Summary

Length: 112.5 in Diameter: 6 in Mass (without motor): 8.9 kg Weight (without motor): 87.2 N/19.6 lb Motor: AeroTech K1275R

Recovery system: Redundant Missile Works RRC2+ altimeters will deploy a 30” elliptical drogue parachute at apogee, and a 72” elliptical main parachute at 800 ft (AGL). A separate pair of RRC2+ altimeters will eject the nosecone and attached payload bay at 1000 ft (AGL), which will descend untethered under its own 42” elliptical parachute.

The milestone review flysheet is a separate document

AGSE/ Payload Summary

Title: Project scension

A six-wheeled rover with rocker-bogie suspension will autonomously:

identify and navigate as needed to a payload lying on the ground pick up the payload with a robotic arm identify and navigate as needed to the horizontally positioned rocket insert the payload into the rocket

The team or other personnel will manually:

move the rocket to a vertical launch position install the igniter launch the rocket

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II. Changes made since PDR

Changes to Vehicle Criteria

Three changes have been made to the vehicle criteria since the PDR:

1. The motor has been upgraded to the AeroTech K1275R, after the subscale test flight indicated that RockSim likely overestimates the altitude achievable by the K1100T.

2. Missile Works RRC2+ altimeters will be used instead of the RRC3 model. The extra features of the RRC3 (e.g. the third deployment output) are not needed.

3. The main altimeter bay will be separated into two compartments by a central bulkhead covered with aluminum foil. The deployment altimeters on one side will be shielded from the GPS transmitter on the other side.

Changes to AGSE/ Payload Criteria

1. The laser ranging system has been removed and the Pixy Camera will operate on its own.

2. The Arduino Uno has been replaced with BeagleBone which is coded in python.

3. The center bogies have been redesigned to be adjustable in the placement on the body of the AGSE.

4. The wheel has been redesigned to be a triacontagon (30 sided polygon).

5. The position of the robotic arm has been changed from the top to the front mouth of the body.

Changes to Project Plan

1. The budget plan and funding plan have been updated to more accurately represent the monetary status of the team.

PDR Feedback

1. The power plant idea is very creative!

Thanks!

2. Can the team explain why it chose a 6’ rail? The motor provided is very aggressive, but the forward rail button does not have much room on the rail.

The team has adjusted the rail size to 8’ in order to give the forward rail button a greater distance before leaving the rail.

3. What is the location of the GPS transmitter in regards to the recovery electronics? What kind of EMI shielding will be used?

The GPS transmitter for both sections will be in a separate compartment from the recovery altimeters. The TeleGPS will be in a compartment directly below the altimeters, but there will be

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an aluminum plate between them to shield the altimeters from electromagnetic waves. The EM-506 GPS will be separated by a much greater distance and will still be in a separate compartment.

4. The review team noticed that the eye-bolts being used are open. Will the team weld these shut, or consider forged eye-bolts/u-bolts? Open eye-bolts have a lower failure stress.

The eye-bolts have been replaced with u-bolts.

5. Is there anything preventing the piston from moving backwards?

A piece of coupler will be epoxied in the body tube. The piston will be resting on this coupler during flight and a black powder charge from the opposite side will not be able to push it backwards

6. Traditionally, pistons will push the parachute out, but this design has the piston pulling the chute out. Can the team explain why this configuration is chosen?

This configuration was chosen to keep the main parachute and the payload parachute separate. There is less chance for the two parachutes to tangle in some way. The system has been tested in the subscale and shows proof of concept for this setup.

7. How is the camera imaging system interacting with the laser ranging system?

The laser ranging system has been removed and the camera imaging system will act on its own. The AGSE will use the angle of the camera and the position of the object in the image to determine how far it is. More details can be found in the design review for the AGSE.

8. Is there anything hardcoded as to where the rocket is, or will the AGSE have to find everything?

The AGSE will have to figure things out on its own. The coding will allow the AGSE to determine what adjustments must be made to perform its operations, but positions of objects will not be hardcoded into the AGSE. It is entirely responsive to its environment.

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III. Vehicle Criteria

Design and Verification of Launch Vehicle

Flight Reliability and Confidence

Mission Statement

Project Λscension will use autonomous ground support equipment (AGSE) to retrieve a 4 oz. payload from the ground and secure it within a launch vehicle. The launch vehicle will carry the payload to an altitude of 3000 ft AGL. Upon descending to 1000 ft AGL, the payload bay will be ejected from the launch vehicle, and descend under its own parachute to the ground to be recovered.

Requirements and Mission Success Criteria

In addition to meeting all NASA mission requirements (addressed below), mission success requires that the AGSE:

identify the payload on the ground retrieve the payload insert the payload into the launch vehicle

The launch vehicle must:

be aerodynamically stable reach apogee as close as possible to 3000 ft AGL deploy the drogue parachute at apogee eject the payload bay at 1000 ft AGL deploy the main parachute at 800 ft AGL land safely and undamaged transmit its location so that it can be retrieved

The payload bay must:

secure the payload deploy its parachute when it is ejected at 1000 ft AGL land safely and undamaged transmit its location so that it can be retrieved

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Major Milestone Schedule

The following table presents the schedule of major milestones for the launch vehicle design, construction, testing, operations, and reviews.

Table 2: Major Milestone ScheduleMajor Milestone Date Status

Proposal Submission 10/6/ 2014 CompleteNotification of Selection 10/17/2014 CompleteWeb Presence Established 10/31/2014 CompletePDR Report, Presentation, Flysheet Submitted 11/5/2014 CompletePDR Presentation 11/14/2014 CompleteSubscale Launch Vehicle Completed 12/18/2014 CompleteSubscale Ground Testing 12/19/2014 CompleteSubscale Test Flight 12/20/2014 CompletePiston Parachute Deployment Testing 1/9/2015 CompleteCDR Report, Presentation, Flysheet Submitted 1/15/2015 CompleteCDR Presentation 1/26/2015 In ProgressFull Scale Launch Vehicle Completed 1/30/2015 In ProgressParachute Deployment Ground Testing 2/2/2015 PendingPayload Retaining System Ground Testing 2/3/2015 PendingFull Scale Test Flight 2/7/2015 PendingBack-up Test Flight Date 2/15/2015 If necessary2nd Back-up Test Flight Date 2/22/2015 If necessary3rd Back-up Test Flight Date 2/28/2015 If necessaryFRR Report, Presentation, Flysheet Due 3/16/2015 PendingFRR Presentation TBD PendingLRR 4/7/2015 PendingLaunch Day 4/10/2015 PendingPLAR Due 4/29/2015 Pending

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Design Review

Final Drawings and Specifications

Figure 2: Rocket exploded view

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Figure 3: Side and bottom view of the rocket

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Figure 4: Rocket booster section

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Figure 5: Rocket middle section

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Figure 6: Main parachute piston

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Figure 7: Payload containment bay and nose cone exploded view

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Figure 8: Rendering of the payload containment device

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Figure 9: Description of nose cone and payload containment system

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Final Analysis and Model Results

Final analysis and model results are detailed below in Subscale Flight Results.

Test Results

1. Subscale Test Flight

The subscale test flight is detailed below in Subscale Flight Results.

2. Piston Ejection Mechanism for the Main Parachute

Test Description: The piston ejection mechanism was ground-tested using the middle section of the 2/3-subscale rocket. Video of the tests is posted on the team web site: http://amiwa/rocketowls/. The avionics bay rested on the ground, and the attached body tube (containing the parachute and the piston) was propped up on a cardboard stand as shown in the following diagram. The ejection charge was detonated with a J-tek electric match connected to a 6-volt lantern battery with 15 ft. of copper wire.

Figure 10: Piston Ejection Ground Test

Design Concerns:

1. Will the piston eject cleanly from the body tube past the sheared nylon pins that held the ejected payload bay and nosecone?

2. Will the relatively lightweight piston have sufficient momentum to pull the parachute out of the body tube?

3. Will the parachute be damaged by the ejection charge?

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Test Results:

The test results are summarized in the following table:

Table 3: Piston Ejection Test Results

TrialAmount of

Black Powder (g)

Piston Ejected Cleanly?

Parachute Pulled from Body Tube?

Parachute Damaged by

Ejection Charge?1 1.0 Yes No No2 1.5 Yes Yes No

Discussion of Test Results:

1. In both trials, the piston ejected cleanly from the body tube. The remains of the two sheared nylon pins near the opening were no significant obstruction.

2. In the second trial, 1.5 g of black powder gave the piston sufficient momentum to fully and forcefully deploy the parachute. In the first trial, 1.0 g of black powder ejected the piston, but the parachute was not pulled from the body tube.

3. In both trials, the parachute and shock cord were undamaged by the ejection charge. A 12-inch-square Nomex blanket provided sufficient protection from the hot gases.

Conclusions:

The test results show that the proposed piston ejection mechanism can effectively deploy the main parachute. Further testing will determine the size of the ejection charge required for the full-scale vehicle.

Final Motor Selection

The following motor has been selected:

Table 4: Final Motor Selection

Make Code Diameter Length Weight Burn Time

Total Impulse

Max Thrust

AeroTech K1275R 54 mm 569 mm22.4 in

2061 g4.54 lbs 1.9 s 2132 N-s

480 lb-s1558 N350 lbs

Justification of motor selection:

Rail Exit Velocity: The AeroTech K1275R is an aggressive motor (see the thrust curve below) that will accelerate the vehicle quickly off the launch pad. RockSim estimates an 8-ft rail exit velocity between 73 – 83 ft/s, depending on the final mass of the vehicle.

Mass Increase: The K1275R permits up to a 25% mass increase between the CDR and the competition launch, as explained in the Mass Statement below.

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Altitude: At the present estimated vehicle weight (19.63 lbs), RockSim predicts an altitude of 4300 ft. AGL with this motor. But the subscale test flight (detailed below) leads us to believe that this overestimates the altitude by 600 ft. or more. Moreover, any mass increase between the CDR and the competition launch will lower the altitude of the vehicle. If full-scale test flights significantly over-shoot the 3000 ft. target, ballast can be added to the vehicle.

Figure 11: Aerotech K1275R Thrust Curve

(http://www.rocketreviews.com/k1275-5081.html)

System Level Functional Requirements

The launch vehicle meets all requirements of the Student Launch Statement of Work. The following tables list each requirement, the design feature that satisfies the requirement, and the means of verification.

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Table 5: Launch Vehicle Requirements and Verification

Requirement Design Feature Verification

1.1 The vehicle shall deliver the payload to, but not exceeding, an apogee altitude of 3,000 feet above ground level (AGL).

With an expected vehicle mass increase of 10 – 20%, the selected AeroTech K1275R will reach 3000 ft AGL.

Full-scale test flights

1.2. The vehicle shall carry one commercially available, barometric altimeter for recording the official altitude used in the competition scoring.

One of the Missile Works RRC2+ altimeters will record the official altitude.

Functional Testing

1.2.1. The official scoring altimeter shall report the official competition altitude via a series of beeps to be checked after the competition flight.

The Missile Works RRC2+ altimeter reports the altitude via a series of beeps.

Functional Testing

1.2.2.3. At the launch field, to aid in determination of the vehicle’s apogee, all audible electronics, except for the official altitude-determining altimeter shall be capable of being turned off.

All audible electronics, except for official scoring altimeter, will be capable of being turned off.

Functional Testing

1.3. The launch vehicle shall be designed to be recoverable and reusable.

Current simulations predict that all rocket components will be recovered within 2300 ft. of the launch pad, and all components are designed to be reusable.

By inspection, and functional testing

1.4. The launch vehicle shall have a maximum of four (4) independent sections.

The launch vehicle has three (3) independent sections. By inspection

1.5. The launch vehicle shall be limited to a single stage.

The launch vehicle has only one stage. By inspection

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1.6. The launch vehicle shall be capable of being prepared for flight at the launch site within 2 hours, from the time the Federal Aviation Administration flight waiver opens.

Flight preparation will be completed in less than 2 hours. A checklist will be used to ensure that flight preparation is efficient and thorough. The team will have practiced these operations during test flights.

Functional testing

1.7. The launch vehicle shall be capable of remaining in launch-ready configuration at the pad for a minimum of 1 hour without losing the functionality of any critical on-board component.

All onboard electronics draw very little power, and can remain in launch-ready configuration for several hours.

Functional testing

1.8. The launch vehicle shall be capable of being launched by a standard 12-volt direct current firing system.

The AeroTech K1275R is a commercial, ammonium perchlorate motor that will ignite with 12-volt direct current.

Functional testing

1.9. The launch vehicle shall use a commercially available solid motor propulsion system using ammonium perchlorate composite propellant (APCP) which is approved and certified by the National Association of Rocketry (NAR), Tripoli Rocketry Association (TRA), and/or the Canadian Association of Rocketry (CAR).

The launch vehicle will use a TRA certified AeroTech K1275R motor.

By inspection

1.10. The total impulse provided by a launch vehicle shall not exceed 5,120 Newton-seconds (L-class).

The launch vehicle will use a K-class motor, which does not exceed 5,120 N-s total impulse.

By inspection

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1.13. All teams shall successfully launch and recover a subscale model of their full-scale rocket prior to CDR. The subscale model should resemble and perform as similarly as possible to the full-scale model, however, the full-scale shall not be used as the subscale model.

The team has launched and recovered a 2/3-scale (4” diameter) model of the full-scale rocket prior to CDR. See the Subscale Test Flight section of the CDR.

By inspection

1.14. All teams shall successfully launch and recover their full-scale rocket prior to FRR in its final flight configuration. The rocket flown at FRR must be the same rocket to be flown on launch day.

The team will successfully launch and recover the full-scale (6” diameter) rocket prior to FRR in its final flight configuration. See the timeline for anticipated dates.

By inspection

1.14.2.1. If the payload is not flown, mass simulators shall be used to simulate the payload mass.

The team plans to fly the payload in the full-scale demonstration flight.

By inspection

1.14.2.3. If the payload changes the external surfaces of the rocket (such as with camera housings or external probes) or manages the total energy of the vehicle, those systems shall be active during the full-scale demonstration flight.

All payloads will be active during the full-scale demonstration flight. By inspection

1.14.4. The vehicle shall be flown in its fully ballasted configuration during the full-scale test flight.

The vehicle will be flown in its fully ballasted configuration during the full-scale test flight.

By inspection

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1.14.5. After successfully completing the full-scale demonstration flight, the launch vehicle or any of its components shall not be modified without the concurrence of the NASA Range Safety Officer (RSO).

The launch vehicle will not be modified after the full-scale demonstration flight without the concurrence of the NASA RSO.

By inspection

1.15. Each team will have a maximum budget they may spend on the rocket and the Autonomous Ground Support Equipment (AGSE). Teams who are participating in the Maxi-MAV competition are limited to a $10,000 budget while teams participating in Mini-MAV are limited to $5,000. The cost is for the competition rocket and AGSE as it sits on the pad, including all purchased components.

The team has budgeted $1500 for the competition rocket, and $3500 for the AGSE. Throughout development and construction of the rocket and AGSE, the team will be looking for ways to cut costs and stay within the $5000 total budget.

By inspection

1.16.1. The launch vehicle shall not utilize forward canards.

The launch vehicle does not use forward canards. By inspection

1.16.2. The launch vehicle shall not utilize forward firing motors.

The launch vehicle does not use forward firing motors. By inspection

1.16.3. The launch vehicle shall not utilize motors that expel titanium sponges.

The launch vehicle does not use motors that expel titanium sponges.

By inspection

1.16.4. The launch vehicle shall not utilize hybrid motors.

The launch vehicle uses commercially available solid APCP motors.

By inspection

1.16.5. The launch vehicle shall not utilize a cluster of motors.

The launch vehicle uses only a single motor. By inspection

Table 6: Recovery Requirements and Verification

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Requirement Design Feature Verification

2.1. The launch vehicle shall stage the deployment of its recovery devices, where a drogue parachute is deployed at apogee and a main parachute is deployed at a much lower altitude.

Redundant Missile Works RRC2+ altimeters will eject a drogue parachute at apogee, the payload bay at 1000 ft, and a main parachute at 800 ft.

By inspection

2.2. Teams must perform a successful ground ejection test for both the drogue and main parachutes. This must be done prior to the initial subscale and full scale launches.

Successful ground ejection tests will be performed prior to initial subscale and full scale launches.

By inspection

2.3. At landing, each independent section of the launch vehicle shall have a maximum kinetic energy of 75 ft-lbf.

Current simulations predict that all vehicle sections will land with less than 75 ft-lbf of kinetic energy.

The team will use simulation results to calculate the kinetic energy of each vehicle section at landing.

2.4. The recovery system electrical circuits shall be completely independent of any payload electrical circuits.

There are no payload electrical circuits. By inspection

2.5. The recovery system shall contain redundant, commercially available altimeters. The term “altimeters” includes both simple altimeters and more sophisticated flight computers. One of these altimeters may be chosen as the competition altimeter.

The recovery system will contain redundant Missile Works RRC2+ altimeters to deploy the parachutes. One of the RRC2+ altimeters will be used as the competition altimeter.

By inspection

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2.6. A dedicated arming switch shall arm each altimeter, which is accessible from the exterior of the rocket airframe when the rocket is in the launch configuration on the launch pad.

Both RRC2+ altimeters will have separate external arming switches accessible when the rocket is in launch position.

By inspection

2.7. Each altimeter shall have a dedicated power supply.

Each altimeter will have a dedicated 9V power supply. By inspection

2.8. Each arming switch shall be capable of being locked in the ON position for launch.

The arming switches will require a straight-edged screwdriver to lock them in the ON position.

By inspection

2.9. Removable shear pins shall be used for both the main parachute compartment and the drogue parachute compartment.

All parachute compartments are attached with #2 nylon shear pins. By inspection

2.10. An electronic tracking device shall be installed in the launch vehicle and shall transmit the position of the tethered vehicle or any independent section to a ground receiver.

An Altus Metrum TeleGPS tracking device will be installed in the launch vehicle.

By inspection

2.10.1. Any rocket section, or payload component, which lands untethered to the launch vehicle shall also carry an active electronic tracking device.

The untethered payload compartment will have its own GPS tracking device.

By inspection

2.10.2. The electronic tracking device shall be fully functional during the official flight at the competition launch site.

The GPS tracking devices will be fully functional at the competition launch site.

Functional testing

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2.11.1. The recovery system altimeters shall be physically located in a separate compartment within the vehicle from any other radio frequency transmitting device and/or magnetic wave producing device.

The recovery system altimeters will be separated from the GPS transmitters by plywood bulkheads covered with aluminum foil.

By inspection

2.11.2. The recovery system electronics shall be shielded from all onboard transmitting devices, to avoid inadvertent excitation of the recovery system electronics.

The recovery system electronics will be shielded from the GPS transmitters by plywood bulkheads covered with aluminum foil.

By inspection

2.11.3. The recovery system electronics shall be shielded from all onboard devices which may generate magnetic waves (such as generators, solenoid valves, and Tesla coils) to avoid inadvertent excitation of the recovery system.

2.11.4. The recovery system electronics shall be shielded from any other onboard devices which may adversely affect the proper operation of the recovery system electronics.

Workmanship as it Relates to Mission Success

Careful attention to workmanship is critical to mission success, especially with regard to:

Structural integrity of the launch vehicle Proper functioning of the recovery electronics

Structural integrity requires proper bonding of structural elements. This will be accomplished by the following practices:

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Epoxy resin and hardener will be carefully measured to attain the proper ratio (1:1 by volume)

Surfaces to be bonded will be cleaned with alcohol and lightly sanded Joints will be immobilized until the epoxy has set All bonds will be inspected by a second team member

Proper functioning of the recovery electronics requires that electronics and wiring be properly and securely mounted. This will be accomplished by the following practices:

Electronics will be handled carefully by the edges and stored in ESD bags to avoid damage from static discharge

Altimeters and GPS units will be securely mounted to electronics sleds with nylon standoffs

Wiring connections will be secured by soldering, or with screw terminals, or with snap-together quick-connectors

Quick-connectors will be taped prior to flight Soldering will be inspected for ‘cold joints’ Batteries will be secured with bubble-wrap and quick-ties Wiring will be bundled and routed in such a way that it does not flop around excessively

during flight Continuity of circuits will be tested with a multi-meter

All electronics and wiring will be inspected by a second team member

Additional Planned Component, Functional, and Static Testing

Full-scale ground testing of the payload containment system. With the launch vehicle in a horizontal position, the payload will be inserted through the payload bay doors just below the nosecone. Then the launch vehicle will be raised to a vertical position. The test should determine by inspection whether the payload bay reliably receives the payload, and whether the payload reliably slides into a slot that secures it for launch when the rocket is raised to a vertical position.

Full-scale ground testing of the drogue parachute deployment. The entire full-scale vehicle will be configured for launch and propped against a cardboard stand as in the subscale piston ejection test (see Figure 10 above). The test will determine the amount of black powder required to separate the booster section from the upper sections and deploy the drogue parachute.

Full-scale ground testing of the payload ejection system. The upper sections of the launch vehicle including the nosecone and payload bay will be configured as in the subscale piston ejection test (see Figure 10 above). The test will determine the amount of black powder required to separate the nosecone and attached payload bay from the upper section of the vehicle.

Full-scale ground testing of the piston ejection mechanism for the main parachute. The altimeter bay and middle section of the launch vehicle will be configured as in the subscale piston ejection test (see Figure 10 above). The nosecone and payload bay will already have been ejected, and the remains of the shear pins will still be lodged in the body tube near the forward,

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open end. The test will determine the amount of black powder required for the piston to deploy the main parachute reliably.

Full-scale test flights. One or more full-scale test flights will be performed to determine whether all systems function as expected.

Manufacturing/ Assembly Status and Plans

The following table details the remaining manufacturing and assembly schedule for the full-scale launch vehicle.

Table 7: Remaining Manufacturing and Assembly ScheduleAction To be completed by:

Laser cut fins 1/23/2015Laser cut parts for the payload containment system 1/23/2015Laser cut parts for the altimeter bay 1/23/2015Cut body tubes and motor mounts to size with chop saw 1/23/2015Build 2 booster sections (one is a back-up) 1/26/2015Build piston parachute ejection system 1/26/2015Assemble payload containment system 1/26/2015Assemble altimeter bay 1/26/2015Mount and wire the electronics and switches 1/28/2015Launch vehicle complete, ready for ground testing 1/30/2015Paint the launch vehicle after flight tests are completed 3/22/2015

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The next table details the parts and manufacturing processes for each launch vehicle subsystem.

Table 8: Vehicle Subsystem Parts and Manufacturing ProcessesSubsystem Parts Manufacturing Process

Booster section

Pre-slotted BlueTube body tube

BlueTube motor mount

Pre-cut plywood centering rings and bulkheads

Plywood fins AeroPack motor

retainer

The body tube and motor mount are cut to size with a chop saw.

The body tubes are pre-slotted by the manufacturer for through-the-wall fin mounting.

The fins are laser cut by the team.

All parts are attached with 30-minute epoxy.

Altimeter Bay

BlueTube coupler tube

Pre-cut plywood bulkheads

¼” all-thread rods ¼” brass tubing Plywood electronics

sled Wiring supplies Rotary switches ½” PVC caps to hold

ejection charges U-bolts

The electronics sled is laser cut by the team.

The brass tubing is cut to length with a hacksaw and epoxied to the underside of the sled.

The sled with tubing slides onto the all-thread rods.

The PVC caps are bolted and epoxied to the bulkheads.

Wiring and electronics are mounted with screws and bolts.

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Main Parachute Piston Ejection System


Pre-cut plywood bulkhead

U-bolt and forged eye-bolt

The coupler tube is cut to length with a chop saw.

The pre-cut bulkhead is epoxied into the coupler tube.

The U-bolt and eye-bolt are mounted on opposite sides of the bulkhead.

A ring of coupler tube is epoxied into the body tube below the piston to prevent the piston from sliding backward and compressing the parachute.

Payload Containment Bay

BlueTube body tube and coupler tube


U-bolt ¼” all-thread

rods Aluminum

flanges Aluminum

payload bay doors

Plywood Spring-loaded

hinges Fiberglass nose

cone

The body tube and coupler tube are cut to length with a chop saw.

The bulkheads are attached to the body and coupler tubes with epoxy, screws or removable rivets.

The payload containment system is constructed from plywood parts laser cut by the team and epoxied together.

The aluminum flanges are attached with screws.

The payload bay doors will be milled by the team from sheet metal.

The spring-loaded hinges will be riveted to the body tube.

The nosecone is attached to the payload containment bay with removable plastic rivets.

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Design Integrity

Suitability of shape and fin style

The primary advantage of the selected trapezoidal fin shape is the forward sweep of the trailing edge. This makes it very unlikely that the booster section will land on a fin tip and break it. The aft end of the body tube will most likely hit the ground first.

These fins are not as aerodynamic or lightweight as other fins. But the selected motor has plenty of thrust, and weight and drag are not serious issues for this mission.

Materials in fins, bulkheads, and structural elements

The airframe consists of three sections of 6” diameter BlueTube 2.0. BlueTube 2.0 is a proprietary material manufactured by Always Ready Rocketry. According to the manufacturer, BlueTube requires no reinforcement for subsonic speeds.

The fins, bulkheads, and centering rings are made of plywood. The three fins are made from 3/16” 10-ply aircraft plywood. The ½” bulkheads and centering rings are made from two sheets of ¼” 5-ply birch plywood glued together.

The ogive nosecone is made of fiberglass.

Assembly procedures, attachment and alignment of elements, connection points, and load paths

The three sections of the launch vehicle fit together with 12” sections of BlueTube coupler tube. The coupler and airframe overlap by 6” (1 airframe diameter) at the joints to ensure that the airframe remains straight and rigid during flight.

Where the airframe should separate to deploy parachutes, the sections are secured by two #2 nylon shear pins. Where the airframe should not separate during flight, the sections are secured by four removable plastic rivets.

The following table details the parts and manufacturing processes for each launch vehicle subsystem.

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Table 9: Vehicle Subsystem Parts and Manufacturing ProcessesSubsystem Parts Manufacturing Process

Booster section

BlueTube body tube BlueTube motor

mount Pre-cut plywood

centering rings and bulkheads

Plywood fins AeroPack motor

retainer

The body tube and motor mount are cut to size with a chop saw.

Fin slots will be marked and cut by hand with a rotary tool for through-the-wall fin mounting.

The fins are laser cut by the team.

All parts are attached with 30-minute epoxy.

Altimeter Bay



¼” all-thread rods ¼” brass tubing Plywood electronics

sled Wiring supplies Rotary switches ½” PVC caps to hold

ejection charges U-bolts

The electronics sled is laser cut by the team.

Brass tubing is cut to length with a hacksaw and epoxied to the underside of the sled.

The sled with tubing slides onto the all-thread rods.

The PVC caps are bolted and epoxied to the bulkheads.

Wiring and electronics are mounted with screws and bolts.

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Main Parachute Piston Ejection System


Pre-cut plywood bulkhead

U-bolt and forged eye-bolt

Coupler tube is cut to length with a chop saw.

The pre-cut bulkhead is epoxied into the coupler tube.

The U-bolt and eye-bolt are mounted on opposite sides of the bulkhead.

A ring of coupler tube is epoxied into the body tube below the piston to prevent the piston from sliding backward and compressing the parachute.

Payload Containment Bay

BlueTube body tube and coupler tube


U-bolt ¼” all-thread rods Aluminum flanges Aluminum payload

bay doors Plywood Spring-loaded hinges Fiberglass nose cone

The body tube and coupler tube are cut to length with a chop saw.

The bulkheads are attached to the body and coupler tubes with epoxy, screws or removable rivets.

The payload containment system is constructed from plywood parts laser cut by the team and epoxied together.

The aluminum flanges are attached with screws.

The payload bay doors will be milled by the team from sheet metal.

The spring-loaded hinges will be riveted to the body tube.

The nosecone is attached to the payload containment bay with removable plastic rivets.

Motor mounting and retention

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The motor mount is a 54 mm diameter, 23” length of BlueTube. It is epoxied to three ½” plywood centering rings, and to the three fin tabs inserted through the airframe. The centering rings and fins are epoxied to the airframe. These connection points provide many secure paths to distribute the thrust from the motor to the airframe.

The motor is retained in the motor mount by an AeroPack retainer, pictured below. The two parts are threaded. The part on the right is epoxied to the aft end of the motor mount. After the motor casing is inserted into the motor mount, the left part screws on by hand, and secures the motor in the motor mount.

Figure 12: AeroPack Retainer

Status of verification

The status of verification is found in Table 5: Launch Vehicle Requirements and Verification above.

Drawings of the launch vehicle, subsystems, and major components

See the drawings of the launch vehicle, subsystems, and major components at the beginning of the Design Review section above.

Mass Statement

The current mass estimate is based on RockSim and SolidWorks models, and on component spec sheets. The estimate is preliminary and likely to increase. The Aerotech K1275R can accommodate mass increases of up to 25%, and still reach the 3000 ft. target altitude. Although simulations predict an altitude of 3090 ft. with a 33% mass increase, the subscale test flight indicates that this may be a significant overestimate.

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http://www.apogeerockets.com/bmz_cache/0/0816417fa464971e5dafb5b5e5f3335e.image.700x516.jpg

Table 10: Vehicle Weight, Altitude, and Rail Velocity

vehicle weight w/out motor (lbs)

motorsimulated altitude

(ft.)8 ft. rail exit velocity

(ft./s)

19.63Aerotech K1275R

4280 83

+25%Aerotech K1275R

3355 75

+33%Aerotech K1275R

3090 73

Safety and Failure Analysis

Table 11 below shows the possible failure modes of the vehicle and the mitigations for those failures.

Table 11: Vehicle Failure Modes

Risk Consequence Pre-RAC Mitigation Post-

RAC

Center of gravity is too far aft

Unstable flight 2B-12 Add mass to the nose cone 2B-9

Piston functionality failure

Main chute not deployed, damage to overall vehicle

1C-15

Rigorous testing to will be done to confirm the efficiency of the design

1C-12

Electronic triggering of black powder

Piston not ejected, parachute not deployed, damage to overall vehicle, payload not ejected on descent

2B-12

Rigorous testing will be done to confirm the efficiency of the design, wires will be checked multiple times to ensure functionality

2B-

9

Center of pressure is too far forward

Unstable flight 2B-12

Increase the size of the fins to lower the center of pressure 2B-9

Fin failure Unstable flight, further damage to the rocket

1C-12

Careful construction to ensure proper fin attachment 1C-8

Shearing of Loss of rocket 1C- A material with high shearing 1C-8

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airframe 12 strength will be used

Premature rocket separation

Failure to reach target altitude, failure of recovery system 3A-8

Check the shear pins before launch, test the timers in test launches, calculate the required mass for black powder charges

3A-6

Centering ring failure Loss of rocket 1A-

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Check construction of centering rings for a good fit, check for damage to centering rings pre-launch and post recovery.

2B-6

Bulkhead failure

Damage to payload, avionics, failure of recovery 2C-5

Proper construction, extensive ground testing of removable bulkheads

2C-4

Nose cone

failure

Flight instability, damage to payload bay, unable to re-launch rocket

2C-5 Strong nose cone constructed from fiberglass 2C-4

Table 12 shows the propulsion failure modes and the mitigations for those failure modes.

Table 12: Propulsion Failure Modes


RAC

Motor ignition failure Failure to launch 3B-9 Check continuity, replace

igniter if necessary 3B-3

Motor CATO Loss of rocket 1B-15

Assembly of motors by certified members only 2B-10

Motor mount failure

Motor launches into the body of the rocket, damage to payloads, loss of rocket

1C-12

Proper construction of the motor mount 2C-4

Improper transportation or mishandling

Unusable motor, failure to launch 1C-6

Motors to be handled by certified members only, motors to be stored properly

2C-3

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Subscale Flight Results

Flight Data

Video of the subscale test flight is available on the team web site: http://amiwa/rocketowls/

2/3 Subscale Vehicle Summary

Length: 72 in Diameter: 4 in Stability: 3.2 caliber Mass (without motor): 2.95 kg Weight (without motor): 28.9 N/6.5 lbs. Motor: AeroTech J350W Recovery system: Redundant Missile Works RRC2+ altimeters deploy a 24” elliptical

drogue parachute at apogee, and a 48” elliptical main parachute at 800 ft (AGL).

Figure 13 shows a RockSim design of the subscale launch vehicle.

Figure 13: RockSim Design of the 2/3 Subscale Vehicle

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Comparison with the Full-scale Design

The chief differences between the 2/3 subscale and the full-scale design are:

The subscale payload bay is empty. The subscale payload bay is tethered to the other sections of the rocket. The subscale payload bay pulls out the main parachute; there is no piston deployment.

Despite the empty payload bay, the stability margin of the subscale vehicle (3.2 caliber) is not far from the estimated stability margin of the full-scale design (3.6 caliber).

Flight Results

Launch conditions:

Date: 12/20/2014Location: Friends of Amateur Rocketry site, Mojave DesertWeather: dry, overcastTemp: 45 FWind: calm (3 – 5 mph)Launch angle: 5 degrees

Flight Data:

The RRC2+ altimeters record only the peak altitude. No other flight data was collected.

Altitude estimated by RockSim: 3314 ft. AGLAltitude reported by the RRC2+ altimeter: 2726 ft. AGL

Predicted and Actual Flight Data Discussion

All systems functioned as designed. The flight of the vehicle was straight and stable. Because the winds were calm, it could not be determined if weather-cocking will be an issue under windier conditions. Both parachutes deployed as expected, and the vehicle was recovered undamaged only a few hundred feet from the launch pad.

The most significant result of the test flight is the fact that RockSim overestimated the peak altitude by 600 ft. The error is not due to inaccurate vehicle weight, because the vehicle weight was taken from the fully constructed and equipped subscale vehicle. The error could be due to several other factors (see Karbon, “The Top 5 Reasons Why Your Altimeter and Computer Simulation Don’t Agree”, Peak of Flight Newsletter, Issue 380):

The vehicle’s coefficient of drag is underestimated. The vehicle’s trajectory was slightly non-vertical. The low temperature (45 F) reduced the total impulse of the motor. The total impulse of the motor is lower than advertised due to random variations in

manufacturing. The motor thrust curve used by RockSim is inaccurate.

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We suspect that the first factor (underestimating the Cd) is the most significant, and that RockSim systematically underestimates the Cd (see Van Milligan, “Maximum Simulation Accuracy for RockSim”, Peak of Flight Newsletter, Issues 45, 46).

Subscale photos:

Figure 14: The Rocket Owls with the Subscale Launch Vehicle

Figure 15: The Subscale Altimeter Bay with Redundant RRC2+ Altimeters

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Figure 16: The Subscale Vehicle under Two Parachutes

Impacts on Full-Scale Launch Vehicle

The results lead us to reconsider our motor choice. The simulated altitude with the AeroTech K1100T (from the PDR) is 3011 ft. AGL. We now suspect that the actual altitude with this motor could be closer to 2400 ft. So we have switched to the more powerful K1275R, with a simulated peak altitude of 4300 ft. AGL. We expect the actual altitude with this motor to be closer to 3700 ft. AGL. This leaves room for a 10 – 20% mass increase between the CDR and the competition launch. If the altitude is significantly higher than 3000 ft. in the full-scale test flights, ballast can be added to lower the altitude accordingly.

Recovery Subsystem

The recovery subsystem consists of parachute deployment electronics and mechanisms, three parachutes and their attachment hardware, and two GPS tracking devices. This system must

accurately detect apogee, 1000 ft AGL, and 800 ft AGL reliably deploy parachutes at these altitudes reduce the kinetic energy of each vehicle section to less than 75 ft-lbf at landing transmit the location of each section to a ground station

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The recovery system components are summarized in the following table:

Table 13: Recovery Subsystem Components

section descent weight of section (lb)

drogue parachute

main parachute

attachment scheme

deployment process

untethered payload 4.9

30" elliptical

42" elliptical 5/8" tubular nylon harness, sewn loops, attached to 1/4” U-bolts with 3/16” quick-links.

U-bolts are mounted to 1/2"plywood bulkheads.

Redundant Missile Works RRC2+ altimeters fire black powder charges.

middle 7.2

72" ellipticalbooster 8.8

Order of Deployment

1. The booster section separates at apogee to deploy the drogue chute.2. The nosecone and attached payload capsule are ejected at 1000 ft., and descend under

their own parachute.3. The main parachute is deployed at 800 ft. out the forward end of the middle section.

Figure 17: Recovery Deployment

Parachute, Harnesses, Bulkheads, and Attachment Hardware

Main Parachute Deployment

A piston deploys the main parachute. This is necessary because the main parachute deploys out the forward end of the rocket after the nosecone/payload bay has been ejected. The main chute cannot reliably be blown out of the airframe by an ejection charge; the hot gases simply go

47

around the parachute. Therefore, the parachute is attached to a piston inside the airframe. The piston is pushed out by the ejection charge, and pulls the main chute out with it. Figures 5 and 6 above show the design of the piston and its location in the middle section of the rocket.

Drogue Parachute

Fruity Chute 30” elliptical parachute. Materials: 1.1 oz. rip-stop nylon, 330 lb braided nylon shroud lines, 3/8” nylon bridle, 1000 lb swivel. RockSim estimates a descent rate of 50 ft/s under this parachute.

Main Parachute

Fruity Chute 72” elliptical parachute. Materials: 550 lb nylon, 11/16” nylon bridle, 3000 lb swivel. According to Fruity Chutes, 17 lb. will descend at 20 ft/s under this parachute. Our tethered booster and middle sections weigh 16 lb.

Payload Parachute

Fruity Chute 42” elliptical parachute. Materials: 1.1 oz. rip-stop nylon, 400 lb braided nylon shroud lines, 5/8” nylon bridle, 1500 lb. swivel. According to Fruity Chutes, 6 lb. will descend at 20 ft/s under this parachute. The nosecone and attached payload bay weigh approximately 4.9 lb., so we expect a descent rate somewhat less than 20 ft/s.

Harnesses, Attachment Hardware, and Bulkheads

The drogue and main parachute swivels will be attached with 3/16” stainless steel quick links to a sewn loop in 9 ft long, 5/8” tubular nylon shock cords. Sewn loops at the ends of the shock cords will be attached with quick links to 1/4” steel U-bolts mounted on 1/2” thick plywood bulkheads. The bulkheads will be epoxied into the airframe.

The nosecone and attached payload bay are untethered to the other sections of the rocket. The payload parachute swivel will be attached with a 1/8” stainless steel quick link to the sewn loop of a 3 ft, 3/8” tubular nylon shock cord. The other end of the shock cord will be attached with a quick-link to a 1/4” U-bolt mounted on a 1/2” plywood bulkhead. The bulkhead will be epoxied into the payload bay airframe.

All recovery subsystem materials and hardware are in accord with the recommendations of the parachute manufacturer (Fruity Chutes). For rockets up to 30 lbs., Fruity Chutes recommends:

5/8” tubular nylon shock cord 3/16” stainless steel quick links

For the 5 lb., untethered payload section, smaller hardware is permitted:

3/8” tubular nylon shock cord 1/8” quick links

1/4” steel U-bolts mounted on 1/2” thick bulkheads epoxied into the airframe should be sufficient to withstand the forces of parachute deployment.

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Electrical Components

Deployment Altimeters

Missile Works RRC2+ altimeters have the requisite functionality, are reliable, easy to use, and inexpensive. The RRC2+ is a barometric altimeter with two outputs to initiate two separate flight events, such as deploying parachutes. After each flight, the peak altitude is reported by a series of beeps. A standard 9V battery powers each altimeter.

Recovery System Electrical Schematics

Electrical schematics for the recovery system are shown below. The main vehicle has a recovery subsystem consisting of a main and drogue parachute, and has two sets of e-matches in order to deploy either one. The payload containment device has a similar setup, however, it contains only one parachute and needs only one set of e-matches.

Drawings, Sketches, Block Diagrams, and Electrical Schematics

Figure 18: Electrical schematics for the main recovery system. The altimeters will be connected to a power source, switches, and E-matches for the drogue and main parachute.

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Figure 19: Electrical schematics for the payload recovery system. The altimeters will be connected to a power source, switches, and E-matches for the parachute.

Kinetic Energy at Significant Phases of the Mission

The following table summarizes the kinetic energy of each independent and tethered section of the launch vehicle. The kinetic energy of each section is well below the maximum 75 ft-lb at landing.

Table 14: Kinetic Energy of each Rocket Section

section descent weight of section (lb)

speed under drogue (ft/s)

kinetic energy under drogue

(ft-lb)

speed at landing (ft/s)

kinetic energy at landing (ft-

lb)

untethered payload 4.9 50 190 <20 <31

middle 7.2 50 280 <20 <45

booster 8.8 50 342 <20 <55

Test Results

Ground Testing

Black powder charges will eject the nosecone and attached payload bay, and deploy the drogue and main parachutes. The team mentor will assist with ground testing these ejection charges to

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determine the required amount of black powder, and to ensure that deployment mechanisms are functioning properly. Only the team mentor will handle the black powder.


Table 15 shows the failure modes for the recovery system and the mitigations for these failures

Table 15: Recovery Failure Modes


RAC

Rapid DescentDamage to airframe and

payloads, loss of rocket1B-16

Redundant altimeters, verification testing of the recovery system, simulation to determine appropriate parachute size

1C-12

Parachute deployment failure

Loss of rocket, extreme damage to rocket and all components

1B-16

Ground test of parachute deployment

1C-12

Parachute separation

Loss of parachute, loss of rocket, extreme damage to rocket and all components

2A-15

Strong retention system, load testing

2B-12

Parachute tear

Damage to rocket, loss of parachute, rapid descent resulting in an increased kinetic energy

2B-12

Safety check the parachute for damage, clear parachute bays of any possible defects, properly pack the parachutes

2C-

4

Parachute melt


1C-10

Proper protection from ejection charges, ground testing of recovery system

2C-5

Slow Descent Rocket drifts out of intended landing zone, loss of rocket 2B-9

Verification testing of recovery system, simulation to determine appropriate parachute size

2C-5

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Mission Performance Predictions

Mission Performance Criteria

The primary mission performance criteria for the launch vehicle are:

stable flight 3000 ft. AGL apogee payload ejection at 1000 ft. AGL kinetic energy at landing for each section <75 ft.-lbf

Flight Profile Simulations

The following graph created with RockSim shows the simulated velocity, drag, and altitude of the vehicle from lift-off to apogee.

Figure 20: Simulated Drag, Velocity, and Altitude

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Figure 21: Flight profile simulations

Altitude

Although the simulated altitude of the vehicle is 4300 ft., the subscale test flight indicates that this overestimates the altitude by as much as 600 ft. Moreover, the team expects a vehicle mass increase of 10 – 20% between the CDR and the competition launch, which would lower the expected altitude several hundred feet more. The combination of these factors leads the team to

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expect an altitude at the competition launch close to 3000 ft. If full-scale test flights are significantly higher than 3000 ft., ballast can be added to the vehicle.

Payload Ejection

Redundant Missile Works RRC2+ altimeters will eject the payload bay at 1000 ft. AGL.

Kinetic Energy

Table 14 summarizes the kinetic energy of each independent and tethered section of the launch vehicle. The kinetic energy of each section is well below the maximum 75 ft-lb at landing.

Drift from Launch Pad

Only rough estimates of the vehicle’s drift from the launch pad are possible at this time. The RockSim flight simulations assume that

1. the rocket is launched at a 5-degree angle2. all parts of the rocket descend and drift together under the drogue parachute3. all parts of the rocket descend and drift together under the main parachute4. the vehicle is not buoyed by a thermal column

The third and fourth points introduce some error into the estimates. At 1000 ft AGL, the payload bay is ejected, and it descends untethered under its own parachute. The tethered sections of the rocket descend under a main parachute that is deployed at 800 ft AGL. These facts are not accounted for in the simulation. However, this error should not be very great, since the distance to the ground is small (<1000 ft), and both parts of the rocket should descend at roughly equal speeds (even under separate parachutes).

Thermal columns of air at low altitudes can buoy a vehicle under parachute and extend its drift. In simulations that included random thermal columns, drift was increased by up to 1000 ft. Because thermal columns are random and infrequent, they are not accounted for here. The following table gives rough baseline drift estimates, which assume vehicle drift is not affected by thermal columns.

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Table 16: Drift from Launch Pad (all sections)

wind speed (mph)

drift at 1000 ft AGL (ft.)

total drift at landing (ft.)

0 525 525

5 662 878

10 760 1132

15 970 1560

20 1070 2287

Scale Modeling Results

The scale modeling results can be found in the Subscale Flight Results section.

Stability Margin

The subscale test flight demonstrates the stability of the design. See the Subscale Flight Results section above. With the motor installed, RockSim gives the following estimates for the full-scale vehicle:

Center of Gravity (measured from nose): 67.9 inCenter of Pressure (measured from nose): 89.7 inStability Margin (caliber): 3.6

Figure 22: Stability Diagram

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AGSE/ Payload Integration

The payload will be captured by the AGSE and will be transferred to the payload containment system. The AGSE will have the task of retrieving the payload and safely returning it to the launch vehicle and the payload containment system will have the task of safely transporting the payload throughout the flight of the vehicle. The payload containment has been designed to be compatible with the current AGSE design. The following section describes how the containment system will work alongside the AGSE in order to capture and contain the payload safely throughout the flight and recovery phase.

Figure 23: Description of payload containment and nose cone section

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Figure 24: Rendering of the Payload Containment Device

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Ease of Integration

Integration Plan

Figure 25: Dimensional drawing of the payload containment device.

The payload will be integrated into the vehicle through the payload containment bay shown in Figure 25. The payload will fall into the payload containment area when it is inserted into the rocket. The opening that the payload falls into will be chamfered on the long sides to ensure that the payload falls into place correctly. However, the payload is not secured until the vehicle is lifted upright. When the vehicle is lifted upright, gravity causes the payload to fall into the

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payload slot, which will hold the payload through the flight. The payload slot can be seen to the left of the payload containment area in Figure 25. This containment bay will be secured to a wood sled that slides onto all-thread rods via four all-thread attachment blocks, which are pointed out in the dimensional drawing in Figure 25. This assembly will be between two bulkheads that will prevent it from sliding around on the all-threads during flight. The tracking device will be located on an electronics sled that will be above the payload containment area. It is shown to the right of the payload containment area in Figure 25. Most of the assembly will be constructed using birch plywood, although some aluminum will be used. The components are all rated to withstand the stresses that will be present during boost. Preliminary analysis indicates that with the payload, 30 lbs of stress is added to the bulkhead. This bulkhead is currently planned at 0.5” thick and will withstand this force. The walls of the payload containment area are reinforced with aluminum, so they will be able to withstand the stress exerted on them by the payload. The figure also shows the dimensions for the components that comprise the payload containment device. These dimensions have been set to fit the current design of the vehicle between the payload containment bay and the nosecone.

The payload containment device will be made to fit into the payload section (forward section) of the vehicle. The containment device will be made to slide into the payload section from the fore end. The bottom bulkhead of the containment device will have a section flattened so that it can slide past the spring-loaded doors in the airframe. The payload containment area must line up with the doors or the payload cannot be inserted. The doors are spring-loaded so that no electronics are necessary to operate it. The payload will be pushed through the door by the AGSE in order to contain it since the doors will not open under the weight of the payload by itself. Once the payload containment device has been slid into place, the assembly will be secured to the airframe of the vehicle through a series of locking bolts. These locking bolts will slide through the airframe of the payload section and into the bulkheads of the payload containment device. The locking bolts can be seen in Figure 26 below and above the payload doors. Once the assembly is locked inside the vehicle, the nosecone can slide into the body of the vehicle. The nosecone will also be locked with bolts that extend through the airframe so that it does not come off at any point during the flight. The bottom of the payload section will be attached to a parachute and the recovery electronics will ensure that the sections separate and the parachute deploys at the proper times.

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Compatibility of Elements

Figure 26: The integration of the payload containment device into the launch vehicle.

Aside from the recovery elements within this section of the rocket, all elements in the containment section of the vehicle are mechanical and are compatible. All components have been designed around each other with the single purpose of capturing the payload and returning it safely. The AGSE interfaces with the payload containment system mechanically and will be able to apply enough force to open the doors. The payload containment device is fully compatible with the current launch vehicle design and will integrate into the launch vehicle as shown in figure 26.

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The interfaces that will be present our internal as well as from vehicle to the ground station. The internal interfaces are outlined in the table below.

Table 17: Internal Interfaces

Components Interface

Booster and middle section

These components connect through the shock cord that attaches to the drogue parachute. The shock cord will be attached to a bulkhead from each section so that the sections cannot separate in flight.

Avionics and middle section

The avionics will connect to the middle section through an electronics sled. This sled will be placed in its own bay at the bottom of the middle section and will rest between two bulkheads.

Recovery electronics and parachutes

The recovery electronics will interface with the recovery parachutes through black powder charges. E-matches will be connected to the recovery electronics and these will ignite the black powder charges that separate the sections and eject the parachutes.

Middle section and main parachute piston

The main parachute will not be connected to the forward section. It will be connected to a piston in the middle section through a shock cord. Ejecting the piston will cause the parachute to eject.

Payload recovery electronics and payload section

The payload recovery electronics will be placed on the backside of the payload containment area. The electronics will be secured to a wood piece as shown in Figure 25.

Payload recovery electronics and parachute

The payload recovery electronics will be connected to an E-match. This E-match will be connected to a black powder charge. This charge will cause the complete separation of the payload section with the rest of the main vehicle and will cause the parachute to deploy.

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The vehicle to ground station interfaces are wireless communication interfaces. Both the TeleGPS and the EM-506 GPS will interface with separate ground stations in order to help track the different components during the recovery phase. Both components will have the means to wirelessly communicate with the ground station.

Simplicity of Integration Procedure

Figure 27: Side view and section view of the payload containment device.

The AGSE and containment have been designed to minimize the integration procedures required on launch day. The containment device will be assembled as shown in Figure 25 prior to launch day. The payload doors will be attached to the airframe of the rocket using spring loaded hinges which eliminates the need for any electronic elements associated with the doors. On the containment device, mounts will be in place for both recovery altimeters and a recovery GPS. All wiring will be done prior to launch day. Switches will be placed in the airframe of the vehicle and wire connectors will allow the recovery altimeters to interface with the switches in a simple and easily removable manner. The containment device will slide in using a rail system that will ensure the proper orientation inside the body of the launch vehicle. Locking bolts will be placed to ensure the bottom bulkhead is secure. Since the GPS will be placed above the top bulkhead on the electronics sled, the switch for this component will be placed in the nose cone. The switch will interface with the electronics using a wire connector which is easy to install and remove. The section view in Figure 27 shows where the RRC2+ altimeters will be mounted. The left side

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is the electronics sled that the GPS will be mounted to although all of this will be complete prior to launch day. In summary, the integration procedure on launch day consists of plugging in the electronics, sliding the payload containment device into the body tube, sliding the nose cone into the body tube and securing the entire assembly with locking bolts. The components have been designed to easily fit together and reduce the amount of work needed to perform during launch day.

The full checklist of launch day integration procedures can be found in the Launch Concerns and Operation Procedures section.

Changes to AGSE/ Payload

Components pertaining to AGSE and payload containment were not tested with the subscale and therefore, no changes to either the AGSE or payload containment system pertain to it, although the payload containment system hasn’t been changed. Changes made to the AGSE can be found in the prior section dealing with changes to criteria.

Launch Concerns and Operation Procedures

Final Assembly and Launch Procedures

The following section describes the procedures that will be required to prepare the vehicle during launch. Prior preparation has been optimized in order to reduce the launch preparations as much as possible. A checklist has been prepared that will be printed out and used at all full scale launches. This checklist has the same material as listed here but requires signing off of each step in order to reduce the risk of system failure.

Avionics Bay

Prior to launch day, the recovery system electronics and batteries will be mounted in the avionics bay and all wiring will be completed. The electronics sled will be connected to the bottom bulkhead previously as well. The following procedures are required for preparation of the avionics bay on launch day.

1. Check and verify voltage of batteries

2. Plug in batteries for both altimeters and GPS

3. Connect the wire connectors for switches together

4. Slide the electronics sled into the avionics bay

5. Connect the wire connectors for the drogue and main ejection charge together

6. Connect the bulkheads at both ends

7. Temporarily bridge the terminals for each ejection charge, turn switches to on position and verify continuity and battery voltage

8. Return switches to off position

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Nose Cone/ Payload Containment

Prior to launch day, the recovery electronics for this section will be mounted and the wiring will be completed. The payload containment device will be preassembled as well. The following procedures are required for preparation of the nose cone and payload containment on launch day.


2. Plug in batteries for GPS and both altimeters

3. Connect the wire connectors for both altimeter switches and ejection charges together

4. Slide payload containment section into the body tube of the forward section

5. Secure bottom bulkhead with locking bolts

6. Connect the wire connectors for the GPS switch together

7. Slide the nose cone into the body tube

8. Secure the nosecone and top bulkhead with locking bolts

9. Temporarily bridge the terminals for each ejection charge, turn the switches for the altimeters on, and verify continuity and battery voltage

10. Turn the switches on for GPS and verify functionality


Recovery Systems

The recovery electronics have already been prepared so this section focuses on the ejection charges and parachutes. No prior preparation of ejection charges or parachutes will be completed.

1. Measure out the proper amounts of black powder for drogue ejection charge

2. Install two e-matches into each set of terminals and place ends into the black powder

3. Load black powder for drogue into the cap

4. Cover black powder with cotton wadding and tape off

5. Repeat step 1-4 for the main and containment ejection charges

6. Fold drogue parachute and attach harness to shock cord

7. Wrap the Nomex blanket around the parachute

8. Connect the harnesses on both ends of the shock cord to the U-bolts in drogue bay and on the lower side of the avionics bay ensuring that the shorter side is connected to the avionics bay

9. Fold main parachute and attach harness to shock cord

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11. Connect the harnesses on both ends of the shock cord to the U-bolts in the main bay and on the lower side of the piston ensuring that the shorter side is connected to the piston

12. Fold the payload parachute and attach harness to shock cord


14. Connect the harness on the end of the shock cord to the U-bolt on the bottom of the payload containment section

Motor

No prior preparation will be completed prior to launch day. The motor will be completely disassembled and reload kits will be opened only at the launch field. The instructions for assembling the motor will be on hand and only team members that have previously assembled the motor successfully will be allowed to prepare the motor on launch day.

1. Prepare motor as described by the AeroTech user manual

2. Verify motor assembly with team mentor

3. Load motor into launch vehicle

4. Install motor retention

Setup on Launcher

While performing the procedures of this section, extra care must be taken. Installing igniters into motors and activating electronics connected to energetics pose a hazard. All precautions must be taken to minimize the risk of injury to personnel.

1. Slide vehicle onto launch rail

2. Allow AGSE to perform its operations

3. Lift launch rail upright

4. Turn on electronics one at a time and listen for response from electronics where applicable

5. Install igniter, ensure that the igniter is at the top of the motor and place tape over bottom to hold the igniter in place

6. Attach igniter to the ignition system

Troubleshooting

Although testing will be performed to ensure that all components are operating properly prior to launch day, errors may occur that cause certain systems to malfunction. This section addresses certain issues that arise and how to fix those issues.

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Issues with continuity in the altimeters can be determined based on the beeps that come from the component. If continuity is the issue, the wiring of that altimeter will be inspected, a multimeter will be used to determine the position of the discontinuity, and the e-matches will be replaced.

Issues with the igniter will be determined when the motor fails to ignite. If this happens, a few minutes will be allowed to pass and the igniter will be inspected and replaced if needed.

If either GPS fails to transmit the data, the electronics will have to be inspected and the ground stations will be troubleshooted. First the wiring and the functionality of the GPS component will be analyzed. If everything is in place, the programs on the ground station responsible for the GPS that is not transmitting data will be inspected to determine if the ground station is responsible for the error.

Post-Flight Inspection

The post-flight inspection will be conducted to determine what happened during the flight. The post-flight inspection consist of analyzing the components of the vehicle and listening to the altimeters for the altitude.

First, the altimeters will be removed and the altitude will be determined through a series of beeps. The parachutes will be inspected for any holes or tears. The body tubes will be inspected for any deficiencies that may have been caused by the flight. Finally, the payload will be inspected to determine whether any damage has occurred.

The following pages are the official checklist that are to be printed out and used on launch day.

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Rocket Owl’s Launch Procedure Checklist

All of the following steps must be completed prior to launch. Each step must be signed off by at least two team members that witnessed its completion. Following this procedure will reduce the risk of any system malfunction during flight. After the checklist is complete, the team leader and safety officer should inspect the launch vehicle and verify flight readiness.

Avionics Bay


2. Plug in batteries for both altimeters and GPS

3. Connect the wire connectors for switches together

4. Slide the electronics sled into the avionics bay

5. Connect the wire connectors for the drogue and main ejection charge together

6. Attach bulkheads at both ends

7. Temporarily bridge the terminals for each ejection charge, turn switches to on position and verify continuity and battery voltage


Nose Cone/ Payload Containment


2. Plug in batteries for GPS and both altimeters

3. Connect the wire connectors for both altimeter switches and ejection charges together

4. Slide payload containment section into the body tube of the forward section

5. Secure bottom bulkhead with locking bolts

Initial Initial

1. __________ __________

2. __________ __________

3. __________ __________

4. __________ __________

5. __________ __________

6. __________ __________

7. __________ __________

8. __________ __________

1. __________ __________

2. __________ __________

3. __________ __________

4. __________ __________

5. __________ __________

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6. Connect the wire connectors for the GPS switch together

7. Slide the nose cone into the body tube

8. Secure the nosecone and top bulkhead with locking bolts

9. Temporarily bridge the terminals for each ejection charge, turn the switches for the altimeters on, and verify continuity and battery voltage

10. Turn the switches on for GPS and verify functionality


Recovery Systems

1. Measure out the proper amounts of black powder for drogue ejection charge

2. Install two e-matches into each set of terminals and place ends into the black powder

3. Load black powder for drogue into the cap

4. Cover black powder with cotton wadding and tape off

5. Repeat step 1-4 for the main and containment ejection charges

6. Fold drogue parachute and attach harness to shock cord


8. Connect the harnesses on both ends of the shock cord to the U-bolts in drogue bay and on the lower side of the avionics bay ensuring that the shorter side is connected to the avionics bay

9. Fold main parachute and attach harness to shock cord

6. __________ __________

7. __________ __________

8. __________ __________

9. __________ __________

10.__________ __________

11.__________ __________

1. __________ __________

2. __________ __________

3. __________ __________

4. __________ __________

5. __________ __________

6. __________ __________

7. __________ __________

8. __________ __________

9. __________ __________

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11. Connect the harnesses on both ends of the shock cord to the U-bolts in the main bay and on the lower side of the piston ensuring that the shorter side is connected to the piston

12. Fold the payload parachute and attach harness to shock cord


14. Connect the harness on the end of the shock cord to the U-bolt on the bottom of the payload containment section

Motor

1. Prepare motor as described by the AeroTech user manual

2. Verify motor assembly with team mentor

3. Load motor into launch vehicle

4. Install motor retention

Launch Pad

1. Slide vehicle onto launch rail

2. Allow AGSE to perform operations

3. Lift launch rail upright

4. Install igniter ensuring that the igniter is inserted completely into the motor and apply tape at the bottom

5. Attach igniter to the ignition system

10. __________ __________

11. __________ __________

12. __________ __________

13. __________ __________

14. __________ __________

1. __________ __________

2. __________ __________

3. __________ __________

4. __________ __________

1. __________ __________

2. __________ __________

3. __________ __________

4. __________ __________

5. __________ __________

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We, the team leader and safety officer, have verified that each component of the vehicle has been inspected and is flight ready.

Team Leader________________________________ Date__________________________

Safety Officer_______________________________ Date__________________________

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Safety and Environment (Vehicle and AGSE/ Payload)

Updated Preliminary Analysis of Failure Modes

Safety Officer

Alex will serve as the team’s safety officer. Alex is TRA Level 1 certified and will be First Aid certified in the near future. The safety officer’s responsibilities in regards to the vehicle include safety analysis, risk mitigation, creating launch procedure checklists, and communication on safety awareness.

Updated Hazard Analyses

Table 18 below shows the possible failure modes of the vehicle and the mitigations for those failures.

Table 18: Vehicle Failure Modes


RAC

Center of gravity is too far aft

Unstable flight 2B-12 Add mass to the nose cone 2B-9

Piston functionality failure

Main chute not deployed, damage to overall vehicle

1C-15

Rigorous testing will be done to confirm the efficiency of the design

1C-12

Electronic triggering of black powder

Piston not ejected, parachute not deployed, damage to overall vehicle, payload not ejected on descent

2B-12

Rigorous testing to will be done to confirm the efficiency of the design, wires will be checked multiple times to ensure functionality

2B-

9

Center of pressure is too far forward

Unstable flight 2B-12

Increase the size of the fins to lower the center of pressure 2B-9

Fin failure Unstable flight, further damage to the rocket

1C-12

Careful construction to ensure proper fin attachment 1C-8

Shearing of airframe Loss of rocket 1C-

12A material with high shearing strength will be used 1C-8

Premature rocket separation

Failure to reach target altitude, failure of recovery system

3A-8 Check the shear pins before launch, test the timers in test launches, calculate the

3A-6

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required mass for black powder charges

Centering ring failure Loss of rocket 1A-

15

Check construction of centering rings for a good fit, check for damage to centering rings pre-launch and post recovery.

2B-6

Bulkhead failure

Damage to payload, avionics, failure of recovery 2C-5

Proper construction, extensive ground testing of removable bulkheads

2C-4

Nose cone failure

Flight instability, damage to payload bay, unable to re-launch rocket

2C-5 Strong nose cone constructed from fiberglass 2C-4

Table 19 shows the possible failure modes of the AGSE.

Table 19: AGSE Failure AnalysisRisk Consequence Pre-

RAC

Mitigation Post-RAC

AGSE collides with launch rail

Launch rail is possibly damaged, knocked over, or rocket sustains damage

1C-9

Safety officer will jump to hit a turn off button on the AGSE if it appears to be heading towards a collision

2C-5

AGSE collides with nearby objects

AGSE sustains damage from collision, object falls over obstructing path

1C-12


2C-5

AGSE circuitry sparks

Electrical system within AGSE body is destroyed, AGSE loses functionality

2B-16

Circuits will be continuously checked throughout assembly,

2B-12

AGSE power source malfunction

AGSE loses functionality2B-16

Add additional battery assembly to maintain proper voltage

2B-12

Pivot bracket failure

Arm is unable to reach payload, Arm is unable to retreat upward once grabbing payload

1C-10

Pivot bracket will undergo rigorous testing to ensure functionality

1C-8

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AGSE runs over feet Injured foot/feet

1C-8

Safety officer will ensure spectators remain ten feet away from AGSE during operation

1C-6

AGSE collides with shins Bruised shins

1C-8


1C-6

AGSE camera system follows spectator

AGSE fails to retrieve payload2C-5

Safety officer will turn off the AGSE, reposition the device, then restart

2C-4

Table 20 below shows the failure modes of the propulsion subsystem as well as the mitigations for those failure modes.

Table 20: Propulsion Failure Modes

Risk Consequence Pre-RAC Mitigation Post- RAC

Motor ignition failure Failure to launch 3B-9 Check continuity, replace

igniter if necessary 3B-3

Motor CATO Loss of rocket 1B-15

Assembly of motors by certified members only 2B-10

Motor mount failure

Motor launches into the body of the rocket, damage to payloads, loss of rocket

1C-12

Proper construction of the motor mount 2C-4

Improper transportation or mishandling

Unusable motor, failure to launch 1C-6

Motors to be handled by certified members only, motors to be stored properly

2C-3

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Table 21 below shows the recovery failure modes and the mitigations for those failures.

Table 21: Recovery Failure Modes


RAC

Rapid Descent Damage to airframe andpayloads, loss of rocket

1B-16

Redundant altimeters, verification testing of the recovery system, simulation to determine appropriate parachute size

1C-12

Parachute deployment failure

Loss of rocket, extreme damage to rocket and all components

1B-16

Ground test of parachute deployment

1C-12

Parachute separation

Loss of parachute, loss of rocket, extreme damage to rocket and all components

2A-15

Strong retention system, load testing

2B-12

Parachute tear


2B-12

Safety check the parachute for damage, clear parachute bays of any possible defects, properly pack the parachutes

2C-

4

Parachute melt


1C-10

Proper protection from ejection charges, ground testing of recovery system

2C-5

Slow Descent Rocket drifts out of intended landing zone, loss of rocket 2B-9

Verification testing of recovery system, simulation to determine appropriate parachute size

2C-5

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Updated Listing of Personnel Hazards

Listing of Personnel Hazards and Safety Hazard Data

A thorough evaluation of the possible hazards associated with the vehicle has been made with respect to the user as well as the environment. Precautionary measures are being taken to ensure that no harmful or explosive substances will be misplaced or misused. A listing of personnel hazards and evidence of understanding of safety is provided in the sections below.

Launch Site Safety

Before launch day, the team will receive training in hazard recognition and accident avoidance; on the day of the launch, the safety officer will perform a safety check on the motor, payload, and recovery subsystems. The team will conduct a safety briefing both before and after each launch where the recognized hazards will be discussed as well as methods for mitigation.\

Table 22: Tripoli minimum distance table

Source: http://www.tripoli.org/LinkClick.aspx?fileticket=RhLaGq2C%2bHY%3d&tabid=38

Certification

An individual must be certified by either the NAR or TRA to purchase and use high-power rocket motors. The team leader, Aaron (TRA #14870), and the team’s mentor, Rick Maschek (TRA #11388), are TRA Certified Level II. The certified members of the team are aware of the risks of high-power rocketry and will help the safety officer ensure a safe launch environment.

Motor Handling and Storage

High-power rocket motors contain highly flammable substances such as black powder or ammonium perchlorate. Therefore, they are considered to be hazardous materials or explosives for shipment purposes by the US Department of Transportation (DOT). The team is aware of and will follow all DOT regulations concerning shipment of hazardous materials. These regulations are contained in the Code of Federal Regulations (CFR) Title 49, Parts 170-179 and specify that it is illegal to send rocket motors by commercial carriers or to carry them onto an airliner. NFPA 1127 Section 4.19 contains the storage requirements of motors over 62.5 grams. The team will store all high-power rocket motors, motor reloading kits, and pyrotechnic modules at least 7.6 meters (25 feet) from smoking, open flames, and other sources of heat.

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The Tripoli Rocketry Association and the National Association of Rocketry have adopted the National Fire Protection Association (NFPA) 1127 as their safety code for all rocket operations. A general knowledge of these codes will be required of all team members. All members of the team will demonstrate competence and knowledge in handling, storing, and using high-powered motors. These include all reloadable motors, regardless of power class, motors above the F-class, and those which use metallic casings.

Adhesive Safety

Much of the construction of the vehicle and payloads require the use of epoxy. Any use of epoxy will be done on construction or lab tables in a well-ventilated area and all team members present are required to wear dust masks and gloves. Acetone or isopropyl alcohol will be available along with a fully equipped first aid kit in the event that there is any contact of adhesive to skin.

Tool Safety

When using power tools during construction each member of the team was required to learn how to appropriately use the tool in question and follow all required safety protocols. Detailed in Table 23 are the tools used in construction of the subscale rocket expected to be used to build the full scale rocket, their hazards, and risk mitigation. In addition, each team member has completed an online safety course for the use of the machine shop on the Citrus College campus.

Table 23: Tool SafetyTool Risk Pre-

RACMitigation Post-

RACBand Saw Eye or respiratory irritation,

bodily harm.2C-5 Protective eyewear,

instruction on how to safely use the tool, read the user’s manual.

2C-3

Power Sander Eye or respiratory irritation. 2C-4 Protective eyewear and gloves.

2C-2

Power drill Eye or respiratory irritation, bodily harm.

2C-4 Protective eyewear, instruction on how to safely use the tool, read the user’s manual.

2C-2

Solder Iron Inhalation may cause pneumoconiosis, tin poisoning, or lung irritation.

2C-4 Research soldering methods, always work with a wet cloth to wipe solder off the iron, work in a well ventilated area under bright light.

2C-2

Laser cutter Irritation or damage toeye

3C-4 Team members doing laser cutting will take a class at the local build shop before doing any cuts for the team.

3C-2

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Lathe Eye or respiratory irritation, bodily harm.


3C-2

Mill Eye or respiratory irritation, bodily harm.


3C-2

California Designation of Cargo Section 27903.

(a) Subject to Section 114765 of the Health and Safety Code, any vehicle transporting any explosive, blasting agent, flammable liquid, flammable solid, oxidizing material, corrosive, compressed gas, poison, radioactive material, or other hazardous materials, of the type and in quantities that require the display of placards or markings on the vehicle exterior by the United States Department of Transportation regulations (49 C.F.R., Parts 172, 173, and 177), shall display the placards and markings in the manner and under conditions prescribed by those regulations of the United States Department of Transportation.72

(b) This section does not apply to the following:

(1) Any vehicle transporting not more than 20 pounds of smokeless powder or not more than five pounds of black sporting powder or any combination thereof.

The Tripoli Rocketry Association and the National Association of Rocketry have adopted the National Fire Protection Association (NFPA) 1127 as their safety code for all rocket operations. A general knowledge of these codes will be required of all team members. All members of the team will demonstrate competence and knowledge in handling, storing, and using high powered motors. These include all reloadable motors, regardless of power class, motors above the F-class, and those which use metallic casings.

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Environmental Concerns

Table 24 below shows the environmental hazards that are present during the launch of the vehicle.

Table 24: Environmental Hazards

Hazards to the Rocket Description

Rocket Landing in Wheat Field

On descent, the rocket may land in a nearby wheat field. This will make locating the rocket difficult.

Wind Blowing Parachute

On descent, the winds may catch the rocket and blow it in an undesired direction or location.

Rocket Lands in nearby road

On descent, the rocket may land in the middle of a road. This would both disrupt traffic and put the rocket in danger.

Heavy Winds Interfere with Launch

The wind in the area may begin to pick up and put the launch process at risk. In this case, the launch may be delayed or canceled altogether.

Force of wind opens payload doors

At any point during the rocket’s flight the payload doors may be at risk of opening due to forces caused by strong winds. If the payload compartment opens, the stability of the vehicle may be compromised.

Electronics landing in water

On descent, the rocket may land in water. If submerged, the electronics within the rocket would be at risk.

Hazards to the Environment Description

Rocket booster section lands in water

On descent, the rocket may land in a location with water. If the booster section of the rocket is submerged, chemicals from the motor can pollute the water.

Rocket hits a birdDuring the launch process, a flock of birds may be flying overhead in such a manner that the rocket blows through them. The rocket may harm or cause loss of life among the wild life.

Bird hits the parachute

On descent, a flock of birds may be flying by and interact with the parachute in a way that could compromise the functionality of the parachute.

Falls into air ventOn descent, if there are any nearby structures, the rocket may land into or on top of an air vent. This may cause damage to the rocket or cause a polluted environment from booster section chemicals.

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The team will keep all our work environments and launch sites free of trash and dispose of all waste safely and responsibly. With respect to the environment, the team has made efforts to recycle all the materials from the previous rocket owls and will continue to work efficiently without creating excess waste. Any materials that are disposed of will be checked to see if they can be thrown away normally or if it needs to be done through special methods or through specific channels.

Disposal of Rocket Motors

All used or misfired rocket motors will be disposed of by soaking them in water until the propellant grains fall apart. The materials used in the motors are not harmful to personnel or to the environment and are therefore safe to dispose of normally after being soaked.

Risk Assessment Break-Down

The following tables break down the meanings of the qualitative and quantitative methods of assessing the risks associated with Project Λscension.

Table 25: Project Risk Quantitative AssessmentLikelihood Impact Level

5Dire

4Major

3Medium

2Minor

1Trivial

5Certain

25 20 15 10 5

4Likely

20 16 12 8 4

3Possible

15 12 9 6 3

2Unlikely

10 8 6 4 2

1Remote

5 4 3 2 1

Table 26: Project Risk Qualitative AssessmentLikelihood Impact Level

1-High 2-Medium 3-LowA-High 1A 2A 3AB-Medium 1B 2B 3BC-Low 1C 2C 3C

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IV. AGSE/ Payload Criteria

Testing and Design of AGSE/ Payload Equipment

Design Review

System Level Design Overview

Mission Statement and Requirements

The AGSE consist of a single Autonomous Rover system. The goal of this system is to capture and contain a provided payload inside the payload bay of the project Ascension launch vehicle. The fundamental order of operations and mission requirements for the system will are as follows.

● The AGSE will be powered, paused and activated using the master switch● The camera subsystem will locate the payload, and track it● The main computer will use data from the camera subsystem to navigate to the payload● The payload retrieval subsystem will obtain the payload● The camera system will locate the launch vehicle and its payload bay using color

detection● The main computer will use data from the camera subsystem to navigate to the launch

vehicle● The payload retrieval subsystem will load the payload into the launch vehicles payload

bay for launch. The functional requirements for the successful completion of the AGSE mission objectives are detailed in Table 27, along with the corresponding subsystem that addresses those functional requirements.

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Table 27: AGSE Subsystem Overview

Subsystem Functional Requirements

Selection Rationale Selected Concept

Characteristics

Body The AGSE system must be self-contained and mobile over Martian-like terrain

In order to obtain the payload, the body will transport all AGSE subsystems to the payload

An aluminum chassis, rocker bogie system and wheel assemblies

A lightweight and durable structure

Camera Subsystem

Determine the angle of rotation and distance necessary to orient the AGSE towards or away from the payload, rocket or a hazard (target objects), and to track those objects

The AGSE must have a means of tracking target objects, and differentiating them from hazards with the goal of navigating the AGSE to those target objects

Use image analysis to determine the orientation of an object relative to the AGSE

Collect and analyze image data.

Payload Retrieval

Subsystem

To physically retrieve and transport the payload from its location to the launch vehicle

Retrieving the payload requires a mechanical process (gripping and lifting) with precise movements

A robotic arm The arm will physically grip and lift the payload

Main Computer

To manage all AGSE subsystem operations and data acquisition and run the custom designed on board software.

Each subsystem will acquire large volumes of data that will need to be communicated to other subsystems. Therefore a high powered processor must be utilized

To acquire digitized data and operate all AGSE subsystems

Collect, analyze and transmit data.

Power Supply

To provide power to all AGSE subsystems

All subsystems will require a supply of power. A central power source eliminates complexity.

A system of power banks

A 50,000 mAh bank to power the micro controllers, and a 26,000 mAh power bank to power the motors

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Figure 28: AGSE Isometric System Overview

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Figure 29: AGSE Exploded System Overview

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Figure 30: AGSE System Master Switches

System Level Analysis and Testing

Due to the fact that AGSE manufacturing has not been completed, no analysis or testing has been done at the system level. This testing will commence as soon as the AGSE is completed, meanwhile, subsystem level and component level testing and analysis is in progress with some completion. These tests and analysis details are discussed in the Subsystem Level Analysis and Testing sections.

Subsystem Level Design Overview

Body Subsystem Design Overview

The body must support and transport all AGSE systems and subsystems over terrain comparable to Martian terrain. The body will be comprised of three major components, an aluminum chassis, a “rocker bogie” suspension, and a six wheel servo controlled drive. The design of the body is overviewed in Figures 31 through 61.

Table 28 summarizes the components of the AGSE body, their functional requirements, the selection rational taken into consideration for the selected concepts, and their characteristics.

Table 28: Body Subsystem Component Overview

Component Functional Requirements Selection Rational Selected

Concept Characteristics

ChassisTo physically support all AGSE subsystems

In order to transport the AGSE subsystems, they must all be mounted to a single unit

An aluminum chassis to physically support all AGSE subsystems

Lightweight and durable

Camera MastTo elevate and support the camera subsystem components

The camera must be elevated to obtain a useful field of view

An aluminum shaft and base Durable

6 Wheel Servo/Motor Drive

To provide mobility to the AGSE

To provide a system which allows for high control in steering and drive

6 Wheel servo/motor drive

Controlled by the central computer and T-Rex Motor controllers

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Rocker Bogie Suspension

To allow for the AGSE to drive on uneven terrain, similar to a Martian environment.

The rocker bogie concept is already a well-established design in use on current Mars rover missions.

Rocker bogie suspension

Pivoting of the bogie arms allows for the AGSE to traverse uneven terrain.

Chassis

The chassis is the structural framework for the entire AGSE. All subsystems and their components will be mounted onto it. The chassis will be laser cut from 1/8” 6061-T6 aluminum sheet metal, and assembled using a combination of bolts, L brackets and TIG welding as necessary. The material was selected for its light weight, strength, availability and low cost.

Figures 31-61 in the Body Diagrams section detail the designs and dimensions of the chassis.

Camera Mast

In order for the camera subsystem to function as required, it must be elevated above the AGSE. To accomplish this, an aluminum shaft and base will be installed onto the chassis of the AGSE. Both will be machined from T-6061 aluminum. The shaft will have an outer diameter of 1.125” and an inner diameter of 1.062” to run wiring through. The shaft will be mounted to the circular base, which has a diameter of 3” and will be secured to the chassis of the AGSE. They will be attached using 10-24 tapped holes, made on a mill.

Figures 31-61 in the Body Diagrams section detail the designs and dimensions of the camera mast.

Suspension

The suspension is the system that connects the chassis to the wheel assemblies and allows for motion between the two. For the AGSE, the suspension is also designed to allow for the vehicle to traverse uneven terrain, similar to Martian terrain. For this reason, a rocker bogie design has been selected. The rocker bogie suspension is modeled after a simplified variant of NASA’s design used on the Mars Pathfinder and the Mars Exploration Rover. The design uses two front and rear bogie arms on each side of the chassis which are able to rock up and down independent of one another. Refer to figure 37. The arms pivot from the front and rear and of the central bogie arm. In theory this allows the wheel assemblies to move up and down over uneven terrain and even crawl over objects while the chassis remains level. The rocker bogie suspension will be constructed from rectangular 1/8” hollow 6061-T6 aluminum alloy tubing. The material was selected for its light weight, strength, availability and low cost. The parts will be cut using a band saw and mill, and then TIG welded together to form the structure of the suspension. The bogie arms will each support the wheel assemblies.

Figures 37-42 in the Body Diagrams section detail the designs and dimensions of the rocker bogie session.

Wheel Assemblies/ Motor Drive

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The Wheel Assemblies house the wheels, motor drive and servo steering mechanisms and provide the AGSE with the ability to drive and steer. The design consists of a servo bracket, which is mounted to the six ends of the rocker bogie arms. The servo output shaft runs down through a 0.625” hole in this bracket and into the top face of a second bracket. This face of the bracket is the servo pivot bracket and is secured to a horn on the end of the servo output shaft using 2mm screws. The servo output shaft will be secured to this bracket so that it can turn the bracket. The other face of the wheel bracket, which will be normal to the ground is the motor mount and will have a 0.472” hole for the motor shaft of a 12-volt DC motor. The motor itself will be secured to the motor mount using a series of 2.5mm screws arranged in a circle and the motor shaft will run through the hole and into a wheel spindle. The wheel spindle shaft will tightly fit into a hole in the other end of the wheel spindle. A lock nut will be used on the end to secure it to the wheel hub. The wheel hub itself will be a 30-sided triacontagon. This will allow to be machined on a mill and provide more traction than a smooth circle. The wheel hub will be secured to the wheel with screws that pass through the 6” diameter wheel. All parts will be made from T-6061 Aluminum. Thee brackets will be laser cut from sheet aluminum, the spindles will be lathed and the wheels will be cut on an end mill. All holes will be made using the mill.

Figures 31-61 in the following pages detail the components of the body and provide dimensions, descriptions and some manufacturing notes.

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Figure 31: Body Overview

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Figure 32: Chassis Dimensions

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Figure 33: Chassis Design

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Figure 34: Chassis Dimensions

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Figure 35: Chassis Lid Design

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Figure 36: Chassis Lid Dimensions

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Figure 37: Rocker Bogie Overview

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Figure 38: Center Bogie Design

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Figure 39: Front Bogie Design

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Figure 40: Front Bogie Dimensions

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Figure 41: Rear Bogie Dimensions

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Figure 42: Rear Bogie Design

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Figure 43: Camera Mount Shaft Design

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Figure 44: Camera Mount Shaft Dimensions

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Figure 45: Camera Mount Shaft Base Design

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Figure 46: Camera Mount Shaft Base Dimensions

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Figure 47: Wheel Assembly Design Overview

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Figure 48: Servo Bracket Design

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Figure 49: Servo Bracket Dimensions

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Figure 50: Servo Pivot Bracket Design

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Figure 51: Servo Pivot Bracket Dimensions

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Figure 52: Motor Mount Design

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Figure 53: Motor Mount Dimensions

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Figure 54: Pivot Shaft Washer Dimensions

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Figure 55: Pivot Shaft Washer Dimensions

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Figure 56: Wheel Spindle Design

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Figure 57: Wheel Spindle Dimensions

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Figure 58: Wheel Hub Designs

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Figure 59: Wheel Hub Dimensions

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Figure 60: Wheel Design

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Figure 61: Wheel Dimensions

Camera Subsystem

The camera subsystem is designed to track the position of “target objects” relative to the AGSE. Such objects include the payload or hazards as examples. The camera system will use the angular position of the servos on the pan tilt head to triangulate the position of target objects centered in the Pixy Cam’s frame of view. This position will be communicated to the AGSE’s main computer system so that the AGSE can navigate to the payload and the launch vehicle. The subsystem incorporates a PixyCMUCam5 camera module, a Mini Pan-Tilt head, an Arduino Uno microcontroller. The Pixy camera will be mounted onto the Mini Pan-Tilt head, which will be secured to a cylindrical camera mast constructed of 6061-T6 aluminum tubing. Both the Pixy cam and the Mini Pan-Tilt head will be connected to the Arduino for data acquisition and processing.

Table 29: Camera Subsystem Component Overview

Component Functional Requirements

Selection Rationale Selected Concept

Characteristics

PixyCamCMU5

To take images of the environment so they can be scanned for the payload and hazards using image analysis

The AGSE design must be able to be implemented on a Martian environment. Digital image capture would work in such an environment.

To use image capture and analysis to capture data used for tracking target objects

Color image capture.

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Camera Pan-Tilt Head

To provide pan and tilt the pixy cam, while simultaneously providing measurements of pan and tilt to the subsystem computer for triangulation calculations

The Pan-Tilt head is able to measure the angle of rotation in its pan and tilt servos.

To use measurements of the degree of “pan” and “tilt” in the Pan-Tilt Head to calculate the angle of rotation for triangulating the position of target objects

Pan and tilt the camera head.

Arduino Uno Rev3

To run the custom designed on board software for the subsystem. The main focus of this software will be image analysis and triangulation calculations. Data acquisition, processing and transmission will also be essential.

The Camera subsystem will acquire large volumes of data and will have to run edge detection and color detection algorithms on many images. Therefore it will require a high power processor.

To digitize data for processing and use in other systems and subsystems


Upon system activation the Camera subsystem’s pan tilt head will pan the camera module 360 degrees. During the panning sequence the Pixy camera will collect a video sample of the environment. The images from the video can be analyzed for the payload and hazards using edge color algorithms from the Pixy’s own PixyMon software and edge detection algorithms run by the Arduino. Using the steps of the servos in the pan tilt head the angle of rotation from the front face of the AGSE can be measured and used in triangulation calculations in the Arduino microcontroller. This data will be transmitted to the main computer so that the AGSE can rotate itself to avoid the objects detected as hazards, and face the payload for distance measurements.

Payload Retrieval Subsystem

The payload retrieval system is designed to physically pick up the payload, secure it for transit to the rocket, and contain the payload in the rocket’s payload bay. The payload retrieval subsystem will use a Lynxmotion AL5D robotic arm, a Flexiforce pressure sensor, and an Arduino Uno microcontroller. The arm has 20 inches of reach will consist of four servos giving it four degrees of freedom. The first servo is the HS-805BB shoulder servo. It will be modified to sweep the first section of the arm from 0 to 360 degrees. The second servo is an HS-755HB servo. It will be attached to the end of the first section of the arm, and it will sweep the second half from 0 to 180 degrees. Finally, the wrist grip at the end of the arm has two servos of its own.

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The wrist can rotate a full 360 degrees axial to arm it is mounted on. The grip servo will only rotate enough to securely close the grip.. The camera module will be used to keep the grip centered over the payload and will be fixed to the gripper. The Flexiforce sensor is used to determine when the grip is securely closed around the payload. A Beaglebone black will be used as the microcontroller for the subsystem and is responsible for running the on board custom software which will use reverse kinematics to pick up the payload

Table 30: Payload Retrieval Subsystem Component Overview

Component Functional Requirement

Selection Rational Selected Concept Characteristics

HS-805BB Shoulder Servo

Rotate the shoulder of the arm centered from the base as necessary, with a range of 270 degrees.

To rotate the shoulder of the arm while retaining precision and programmatic control.

HS-805BB servo included in the Lynxmotion kit. It will be modified to have a range of 0 to 270 degrees.

343 oz-in torque, 270 degree range.

HS-755HB Elbow Servos

Connect to the aluminum brackets to rotate the arms with a range of 180 degrees

To rotate the shoulder of the arm while retaining precision and programmatic control.

HS-755HB servo included in the Lynxmotion kit.

183 oz-in torque. 180 degree range

HS-645MG Wrist Servo

Rotate the grip circularly with a range of 180 degrees

To rotate the wrist of the arm while retaining precision and programmatic control.

HS-645MG Servo included in the Lynxmotion kit.

133 oz-in torque. 180 degree range.

HS-422 Gripper

Securely close a grip around the payload for

To close the grip of the arm while retaining precision and programmatic control

HS-422 Gripper included in the Lynxmotion kit

57 oz-in.

PixyCam CMU5

Collect images for edge detection to determine if the payload is off center from the HS-422 gripper.

Edge detection is the most efficient means of searching for an object without relying on ultrasonic sensors.

Arduino compatible camera module to collect images for analysis

Collects image data.

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Flexiforce Pressure Sensor

Determine whether the gripper is sufficiently secure around the payload

A pressure sensor was selected because of the ease of measuring the pressure force in the grip

Flexiforce pressure sensor which produces change in resistance with respect to the change in pressure applied to the sensor.

Measures pressure between payload and gripper.

Beaglebone Black

Collect and analyze data from the Pixy Cam using custom made software to determine the position of the arm relative to the payload. Then use software for reverse kinematics calculations to position the grip around the payload and lift it

The servos need to be controlled and precisely adjusted to retrieve the payload.

To digitize, analyze and transmit data to guide and control the Lynxmotion AL5D arm.


The entire robotic arm unit will be mounted in the space shown in Figure 62, in the mouth of the AGSE chassis, increasing the range of motion and reach of the arm. From this position, the arm will have a total reach of 270 degrees since the chassis will no longer inhibit arm movement.

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Figure 62: Mouth of Chassis Prototype

Once the AGSE has reached the payload the payload retrieval subsystem will activate. On activation the subsystems camera module will begin collecting images. Since the camera module is fixed to the gripper, the gripper will always occupy the same pixel space in the image. Edge detection will be used to determine the position of the payload in the gripper as the gripper is moved towards the payload. If the arm is offset, the images can be used to determine which direction the arm is offset. The arm will be programed to compensate for this error until the image is centered in the frame. This process will continue until the gripper is around the payload. This will also be verified using image analysis. Once the gripper is around the payload, the arm will be programed to close the gripper. As the gripper closes, it will apply more pressure to the Flexiforce sensor. When enough pressure has been applied so that the gripper will not drop the payload, the arm will lift the payload. This specific pressure value will be determined experimentally. The AGSE is then clear to proceed to the rocket. The pressure sensor will continue to be read by the Arduino to ensure that the pressure does not change in transit. When the AGSE reaches the rocket the same process of image analysis and servo control will be used to insert the payload into the launch vehicles payload containment bay. Figures 63-65 show the assembly of the arm, and the different servo components

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Figure 63: Fully assembled AL5D robotic arm

Figure 64: Elbow Servo (Left) and Base Servo (Right) Bracket Mounting

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Figure 65: HS-422 Gripper (left) and Wrist Servo (right)

Main Computer

The main computer is designed to slave all of the system and subsystem microcontrollers, and perform any intensive calculations. The controller used for this system will be an Arduino Mega which was selected for its high processing power. It will receive different kinds of encoded data from each subsystem which must be analyzed to determine what functions must be carried out in the different subsystems. With 54 digital input/output pins and 16 analog input/output pins, the Arduino Mega has sufficient interfacing capabilities. It will be programmed in a modified, open-source version of C/C++ The main computer will also feature a master switch and a pause switch. The master switch will powers on the entire system. The pause switch will temporarily disable all autonomous AGSE subroutines.

Power Supply

The AGSE subsystems will be powered by a network of power banks. The microcontrollers will specifically be powered by a single Allpower Lithium Polymer power banks, providing 5V of electricity with a 50k mAh capacity when wired to the microcontrollers in parallel. The T-Rex motor controllers will draw power from an Anker 26k mAh adjustable voltage lithium power bank. The power bank will be set to 12V to power the 12V motors via the T-Rex controller. The power plans and electrical schematics are further detail the subsystem in the AGSE/Payload Electronics section

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Subsystem Level Analysis & Results

Structural Analysis for AGSE Components

For the Analysis of the AGSE, structural capacity simulations will be done in solid works for specific load bearing structural components. This will take place before manufacturing and ensure that the manufactured components are capable of withstanding any loads or forces they are likely to encounter. The structural capacity testing will be evaluated on the basis the safety factor resulting from the SolidWorks simulations. The full simulation results will be available in Appendices

Completed Structural Analysis

Table 31: Structural Capacity Summary for the Body SubsystemComponent Safety Factor Simulated Load Simulation ResultsChassis Lid 149 10 lb PassServo Bracket 17.5 23 lb PassServo Pivot Bracket 8.80 10 lb PassWheel Adapter Cylinder

55.8 10lb Pass

Planned Structural Analysis

The robotic arm will also undergo structural capacity simulations to ensure that its components do not deform or break under the weight of the arm in specific configurations. Specific attention will be placed on configurations which increase the amount of torque placed on the servos. This will be done before the servo arm testing and as soon as the SolidWorks models are completed for the AL5D arm.

Structural capacity testing will not be necessary for other purchased and assembled components due to lack of structural significance and maturity of the manufacturers design.

Completed Subsystem Level Testing & Results

The testing for the AGSE will consist of component level and subsystem level functional and static test. The static test will be used to confirm the structural capacity analyses and will be carried out on manufactured components or prototypes using equivalent mass weights. The functional test will be carried out on components and subsystems to ensure that they will fulfill their respective functional requirements and the mission objectives. The testing plans are summarized in the tables bellow and are fully detailed in the Planned Testing section of the paper. The completed test and their results are detailed in the following sections.

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Body Testing

Table 32: Test Summary for Body ComponentsComponent Functional Requirements Test Summary Results/Status

Chassis To structurally support all AGSE subsystems

Static test based on the structural capacity analyses

In Progress


To allow for the AGSE to drive on uneven terrain similar to a Martian environment

Prototype for static and dynamic test

Failed/revisions needed

Servo Motor Drive/Wheel

Assembly

To drive and turn the wheels of the AGSE, providing mobility to the system

Prototype one full wheel assembly for static and dynamic testing

In progress

Completed Body Testing & Results

The only testing to be completed for the body subsystem is the prototyping for the rocker bogie suspension. The prototype was manufactured from laser cut wood and assembled using glue and bolts. The dimensions are all half scale to the AGSE’s final designs. Figure 66 shows the prototype.

The prototype Bogie arms were mounted to a laser cut body also constructed to half scale dimensions for testing. Static test were performed on flat terrain to determine if our rocker bogie design was capable of supporting the chassis without collapsing. The chassis collapsed into the bogie arms as seen in Figure 66.

Figure 66: Rocker Bogie Failure

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Revisions are being made to the design with regards to the position of the arms relative to the chassis, and chassis weight. Retesting will take place as soon as this is complete. The static load test and dynamic test will take place after this as well, and plans for those test are detailed in the Planned Testing section of the paper.

Camera Subsystem Testing

Table 33: Test Summary for Camera Subsystem ComponentsComponent Functional Requirements Test Summary Results/Status

Pixy Cam CMU5

To take images of the environment for color and edge detection scanning of target objects and hazards

Use the pixy to detect objects of different shapes and colors in laboratory conditions

In Progress

Pan Tilt Head Use angular measurements and movements of the pixy cam to triangulate the position of target objects and hazards

Mount the Pixy Cam to the pan tilt head and use it to track the position of a colored object within the full range of 180 to the horizontal of the camera and 90 degrees down the vertical of the camera.

In Progress

Arduino Uno Rev 3

To run the custom designed on board software for the subsystem.

The Arduino will be tested in conjunction with the other components of the subsystem.

In progress

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Completed Camera Subsystem Testing & Results

The Pixy Cam CMU5 comes fully assembled with open source software available to run it. PixyMon software is designed to be used directly with the Pixy Cam to upload color signatures to the camera. The color signatures are then referenced by the Arduino to track the location and size of regions in an image based on the color of the object in that region.

To test the Pan-Tilt head for the Pixy Camera, the servos were disconnected from the Pixy and wired directly to an Arduino Uno. Using custom-written software, the servos were individually tested to ensure that each could pan a full 180 degrees, and that the servos would pan or tilt across the correct path. For example, if the center position of the Pixy Camera is forward, it would need to rotate 90 degrees to both its left and right to be as required by the AGSE navigation subsystem’s design.

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Figure 67: Pan/ Tilt servo test schematic

Figure 68: Wiring Setup for Pan-Tilt Servo Test

To ensure the Pixy Camera works as intended, a software called PixyMon was used to calibrate the Pixy Camera to find white objects with a very low range for saturation and hue

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values. The screen, shown locating a white mask on a person’s face with a background of varying colors, is shown in Figure 69 below.

Figure 69: PixyMon Calibration and Testing

As can be seen in the previous figure, the test was successful at demonstrating the Pixy camera’s ability to locate white objects among a background of various colors.

Integrity of Design

Purchased Components

Many of the components in the AGSE are purchased parts designed to work with one another and designed to be interfaced with their respective microcontrollers. The Pixy Camera is designed to work with the PanTilt head, both of which are designed to interface with an Arduino board. The entire Payload Retrieval subsystem is manufactured by Lynxmotion, a reputable company. Given that these components are already purchased from a reputable company, the Integrity of the design for those particular subsystems is already established.

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Manufactured Components

Materials

Manufactured components will all be machined from T6061 aluminum. This material is known to have a high strength and light weight. Furthermore these components underwent structural capacity analyses, all of which reported safety factors above 8.8. The details of these structural capacity analyses are detailed in the Analysis and Results section, and Appendix F.

Physical Integration

The integration of these components has also been simulated within solid works to show how difference components will fit together. So long as the manufactured components are machined to a precision of approximately +/- 1/16th of an inch, the components should still be able to satisfy their functional requirements to a satisfactory degree. Certain components, such as the wheel spindles much be machined to a much higher precision. The smallest end of the spindle much be machined to a precision of +/- 0.0010” in order to fit the wheel assembly and function as required. These factors are taken into greater consideration in the in the Workmanship section of the paper.

Functional Integration

The ability of the different components and subsystems to work with one another will be verified through component and subsystem testing. The completed testing demonstrates the design integrity with respect to their subsystems. These tests were overviewed in the Completed Test & Results section. The logic of the current design is well founded, and even untested subsystems and processes use established methodologies and techniques. For instance, the robotic arm is an established method of object obtainment, and it is designed by Lynxmotion to be interfaced with Arduino boards. Furthermore, the Arduino boards are capable of interfacing with one another, so the mastering and slaving between Arduinos should be functional. Similarly, the Pixy camera design is known to work and interface directly with the Arduino boards, via the ICSP port. This maturity of design in theory is indicative that the AGSE will satisfy its functional requirements and the mission objectives.

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Status of Verification

Table 34: AGSE Requirement Verifications

AGSE Requirement Design Feature Verification Plan Status

Teams will position their launch vehicle horizontally or vertically on the launch pad.

The AGSE’s robotic arm only has 20 inches of reach. Therefore the launch vehicle will be positioned horizontally.

N/A N/A

A master switch will be activated to power on all autonomous procedures and subroutines.

The Master Switch on the main computer will be used to power on all AGSE autonomous procedures.

Test the functionality of the switch using a prototype. Testing will also be done on the final AGSE system.

In progress. Materials are being acquired for construction.

A pause switch will be activated temporarily halting all AGSE procedures and subroutines.

The pause switch on the main computer will be used to pause all AGSE procedures and subroutines.

Test the functionality of the switch using a prototype. Testing will also be done on the final AGSE system.

In progress.

During autonomous procedures, the team is not permitted to interact with their AGSE

The main computer will be programed to manage all AGSE subsystems without human intervention.

The main computer and all AGSE subsystems will be tested using prototyping as well as field testing to ensure that the system can complete it

In progress

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Once the pause switch is deactivated, the AGSE will capture and contain the payload within the launch vehicle.

The payload retrieval system will physically lift and carry the payload for transport. It will also place the payload into the payload bay of the launch rocket.

The payload retrieval system will be tested for its ability to locate and lift the arm using a prototype payload of equivalent dimensions and mass

In progress. Assembly is complete and coding is in progress for the AL5D robotic arm

After the erection of the launch vehicle, a team member will arm recovery electronics.

The recovery electronics will be activated by a pressure sensor once the payload is inside the payload bay.

The recovery electronics will be tested using a prototype and test launches on the subscale rocket.

In progress. Materials are being acquired for construction

The igniter is manually installed and the area is evacuated.

N/A N/A N/A

Once the launch services official has inspected the launch vehicle and declares that the system is eligible for launch, he/she will activate a master arming switch to enable ignition procedures

N/A N/A N/A

The Launch Control Officer (LCO) will activate a hard switch, and then provide a 5-second countdown.

N/A N/A N/A

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At the end of the countdown, the LCO will push the final launch button, initiating launch

N/A N/A N/A

The rocket will launch as designed and jettison the payload at 1,000 feet AGL during descent.

An altimeter will be used to initiate payload jettison at 1,000 feet AGL

Sensors that rely on Earth’s magnetic field are prohibited.

The AGSE will not use any sensors which are dependent on Earth’s magnetic field.

N/A N/A

Ultrasonic or other sound-based sensors are prohibited.

The AGSE will use an image analysis for navigation so no sound based sensors will be necessary

The Camera subsystem will be tested for functionality, precision and consistency by prototyping and field testing.

In progress. Assembly is complete and coding is in progress.

Earth-based or Earth orbit-based radio aids (e.g. GPS, VOR, cell phone) are prohibited.

The AGSE will be navigated by the camera subsystem rather than Earth orbit based radio aids.

The camera subsystem will be tested for functionality, precision and consistency by prototyping and field testing.

In progress. Assembly is complete and coding is in progress.

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Open circuit pneumatics are prohibited.

The AGSE will only use servos and motors for mechanical work, rather than any pneumatic systems.

The servos will be tested for functionality by prototyping and field testing to ensure they can provide the necessary power in various environments and terrains.

In progress. Manufacturing is still being done for the prototypes.

Air breathing systems are prohibited.

The AGSE will only use servos and motors for mechanical work, and the wheels will be machined out of aluminum without pressurized tires. Hence no Air breathing systems will be needed.

The servos will be tested for functionality by prototyping and field testing to ensure they can provide the necessary power in various environments and terrains.

In progress. Manufacturing is still being done for the prototypes.

System Level Functional Requirements

Table 35 details the AGSE requirements from the Student Launch Handbook, and the design feature that addresses them.

Table 35: AGSE RequirementsAGSE Requirement Design Feature Rational

Teams will position their launch vehicle horizontally or vertically on the launch pad.

The AGSE’s robotic arm only has 20 inches of reach. Therefore the launch vehicle will be positioned horizontally.

By positioning the launch vehicle horizontally, the arm only has to reach the height of the launch rails

A master switch will be activated to power on all autonomous procedures and subroutines.

The master switch connected to all of the main power supplies and will be used to power on all AGSE autonomous procedures.

The master switch will be used to cut or allow power to the entire AGSE

A pause switch will be activated temporarily halting all AGSE procedures and subroutines.

The pause switch will be connected to the power supplies used to pause all AGSE procedures and subroutines.

A DPDT switch will be used to cut or allow power to the entire AGSE

During autonomous procedures, the team is not permitted to

The main computer will be programed to manage all

An Arduino Mega has sufficient processing power

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interact with their AGSE AGSE subsystems without human intervention.

to perform this task

Once the pause switch is deactivated, the AGSE will capture and contain the payload within the launch vehicle.

The payload retrieval system will physically lift and carry the payload for transport. It will also place the payload into the payload bay of the launch rocket.

A robotic arm is an established method for object retrieval. Furthermore, Lynx motions Al5D model is well established in its functionality

After the erection of the launch vehicle, a team member will arm recovery electronics.

The recovery electronics will be armed by a rotary switch

A switch will allow for manual activation by one of the team members

The igniter is manually installed and the area is evacuated.

N/AN/A

Once the launch services official has inspected the launch vehicle and declares that thesystem is eligible for launch, he/she will activate a master arming switch to enable ignitionprocedures

N/A N/A

The Launch Control Officer (LCO) will activate a hard switch, and then provide a 5-second countdown.

N/A N/A

At the end of the countdown, the LCO will push the final launch button, initiating launch

N/A N/A

The rocket will launch as designed and jettison the payload at 1,000 feet AGL during descent.

An altimeter will be used to initiate payload jettison at 1,000 feet AGL

Sensors that rely on Earth’s magnetic field are prohibited.

The AGSE will not use any sensors which are dependent on Earth’s magnetic field.

N/A

Ultrasonic or other sound-based sensors are prohibited.

The AGSE will use the camera system to perform triangulation to determine distances

The camera navigation subsystem does not emit sound or ultrasonic waves

Earth-based or Earth orbit-based radio aids (e.g. GPS, VOR, cell phone) are prohibited.

The AGSE will be navigated by the camera subsystem rather than Earth orbit based radio aids.

The camera system will not require any radio transmissions.

Open circuit pneumatics are prohibited.

The AGSE will only use servos and motors for

Servos and motors run off DC electricity and thus do

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mechanical work rather than any pneumatic systems.

not suffer from the effects of pressure and temperature changes open circuit pneumatics do

Air breathing systems are prohibited.

The AGSE will only use servos and motors for mechanical work, and the wheels will be machined out of aluminum without pressurized tires. Hence no Air breathing systems will be needed.

Servos and motors run off DC electricity and thus do not suffer from the effects of pressure and temperature changes open circuit pneumatics do

Workmanship

Purchased Components

Components from the Camera Subsystem, Payload Retrieval Subsystem, and all computer and power supply subsystems were all purchased and thus will meet the high industry standard of workmanship. No custom electronics or PCB’s were designed, and no machining or manufacturing was done. These components only required assembly and integration, both of which are done according to the manufacturer’s instructions and specifications. The components were also purchased from reputable vendors and were tested or planned to be tested to ensure they are working in condition.

Manufactured Components

Schematics have been made for all components that need to be manufactured. The dimensions will be followed to the highest precision possible. That being said, the tools available to machine the AGSE components are very old and as such are very imprecise in their calibration and measurements. With these limitations, it is difficult to achieve industry standard precision, but this is not necessary to satisfy the functional requirements of the components in most cases. However a few components in particular, such as the wheel spindles do have to be machined to a precision of +/- 0.0010” in order to fit the wheel assembly with enough friction to turn the wheel. Such components will be machined and inspected for precision. If the component does not pass inspection, it will be discarded and replaced by another to ensure high precision when it is needed. Specifics on which components need this level of precision are detailed in the Manufacturing Plans.

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Planned Component, Functional, and Static Testing

Due to the fact that the AGSE is still in the manufacturing process, many parts have not been tested. The following sections detail the plans for testing any untested components and subsystems.

Planned Body Testing

Table 36: Test Summary for Body ComponentsComponent Functional Requirements Test Summary Results/Status

Chassis To structurally support all AGSE subsystems

Static test based on the structural capacity analyses

In Progress


To allow for the AGSE to drive on uneven terrain similar to a Martian environment

Prototype for static and dynamic test

Failed/revisions needed

Servo Motor Drive/Wheel

Assembly

To drive and turn the wheels of the AGSE, providing mobility to the system

Prototype one full wheel assembly for static and dynamic testing

In progress

Chassis Testing

The chassis will be tested using the structural capacity simulations completed in the Analysis & Results section before being manufactured. Once manufactured and assembled the body will undergo a series of stress tests. The stress tests will use masses of equal or greater magnitude than those of the actual AGSE components to ensure that the chassis will not deform or break under the resulting loads.

Rocker Bogie Suspension Testing

Once the rocker bogie suspension designs have been revised and prototyped, the rocker bogie will undergo another flat terrain test. If this test is successfully completed, it will move onto static and dynamic stress test to confirm the results of the structural capacity simulations. These tests will be done using mass weights of equal magnitude to the mass in the simulations. Once the designs structural capabilities are confirmed, the suspension will be tested for its ability to traverse uneven terrain through field-testing on Martian like terrain. The required field conditions for successful test completion are hills with a height of at least six inches and positions necessary to test left side, right side and simultaneous hill climbing on the suspension.

Servo Drive/ Wheel Assembly Testing

In order to test the servo drive and wheel assembly design, a single prototype will be fully manufactured and assembled according to full scale specifications. The prototype will be used to confirm the structural capacity test by placing loads on the prototype, equivalent to those found in the SolidWorks mass statement. According to this mass statement, the total mass of the AGSE

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is 50 lbs maximum, so evenly distributed across both suspensions would be 25 lbs, which would be distributed across 3 wheel assemblies for a final load of 8.34 lbs. This load will be placed on the assembly using mass weights and the servo’s and motors will be powered on to ensure that they are powerful enough to turn and drive under the weight of the AGSE. This prototype is still in the manufacturing process, but the SolidWorks simulations in the Analysis & Results section show promising results.

Planned Camera Subsystem Testing

Table 37: Test Summary for Camera Subsystem ComponentsComponent Functional Requirements Test Summary Results/Status

Pixy Cam CMU5

To take images of the environment for color and edge detection scanning of target objects and hazards


In Progress

Pan Tilt Head Use angular measurements and movements of the pixy cam to triangulate the position of target objects and hazards

Mount the Pixy Cam to the pan tilt head and use it to track the position of a colored object within the full range of 180 to the horizontal of the camera and 90 degrees down the vertical of the camera.

In Progress

Arduino Uno Rev 3

To run the custom designed on board software for the subsystem.

The Arduino will be tested in conjunction with the other components of the subsystem.

In progress

The plans for these tests are to use the Pixy Cam to track a prototype payload based on the NASA specifications and the Pan Tilt head movements to determine its distance from the Pixy. The criteria for successful test completion are the ability of the camera to find and track the payload smoothly over the full 180-degree range of pan and 90 degrees of tilt, as well as its ability to measure the distance of the object to a precision/accuracy of one inch.

Planned Payload Retrieval Subsystem Testing

The AL5D robotic arm has been fully assembled but no testing has been completed. The test plans are summarized in Table 38.

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Table 38: Test Summary for Payload Retrieval Subsystem ComponentsComponent Functional Requirements Test Summary Results/Status

Hs-805BB Shoulder

Servo

Rotate the shoulder of the arm centered from the base as necessary, with a range of 270 degrees.

Static and Dynamic test on the servo to ensure that the servo can provide enough torque to rotate the arm, under its own weight and the weight of the payload

In Progress

HS-755HB Elbow Servo

Connect to the aluminum brackets to rotate the arms with a range of 180 degrees


In Progress

HS-645MG Wrist Servo

Rotate the grip circularly with a range of 180 degrees


In Progress

HS-422 Gripper

Securely close a grip around the payload for transport

Static test to determine if the servo can close the grip tight enough to hold the payload without dropping it

In Progress

Pixy Cam CMU5 Camera Module

Collect images for edge and color detection to determine if the payload is off-center from the HS-422 gripper, and the payload bay door on the launch vehicle.


In Progress

Flexiforce Pressure Sensor

Determine whether the gripper is sufficiently secure around the payload

Use an equivalent mass to determine the necessary pressure to secure the payload.

In progress

Arduino Uno Rev 3

Run the custom on board software designed to use input from the pixy cam, and inverse kinematics to move the arm into position to pick up the payload

The Arduino must be tested in conjunction with the other components. The code itself will be tested at the subsystem level

In progress

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Servo Testing

In order to ensure the full functionality of the AL5D Robotic arm within its full range of reach, each servo must be tested independently in in coordination with the other servos to verify that they can support their own respective loads and provide enough torque to rotate the arm under that load. In order to perform these test, the arm will be extended fully with a mass weight equal to the mass of the payload. By doing this, the maximum possible torque will be experienced by the servos, and if the servos are able to function under these forces, it follows that they should be able to function in other arm configurations that place less torque on the servos.

The code must also be tested once it is finished being written to ensure that the AL5D arm is capable of accurately locating and picking up the payload from its position on the chassis of the AGSE. This will be done in laboratory conditions using a prototype payload made from PVC and sand to the exact specifications of the NASA provided payload. Success criteria for this test are the arms ability to successfully locate, grip and lift the prototype payload at least 10 times consecutively. Any failures to pick up the payload will require an analysis to determine which servos failed and how the code can compensate for any mechanical errors.

Planned Main Computer Subsystem Testing

Although each subsystem may work independently of one another, it is important to verify that they are capable of working together to satisfy the mission requirements. The main computer is responsible for managing all subsystems and as such, any testing of the main computers functionality and the soundness of the code it will run will be dependent upon the AGSE systems ability to satisfy the mission goals. This will be tested through a series of field test to simulate the actual competition as best as possible. The success criteria for these test are identical to the mission success criteria.

Manufacturing/ Assembly Status and Plans

The AGSE as a whole is currently under construction, with different subsystems in different phases of construction. The plans and status of each subsystem are detailed in the sections below. The machines used for manufacturing will be used with the permission of the Citrus College Automotive Department.

Body

Body Manufacturing Plans

The manufacturing for the body subsystem is the most extensive, and will involve machining parts on a lathe and mill for the different components of the subsystem. The Bogie arms will be machined using 1/8th inch thick T-6061 aluminum square tubing. The aluminum will be roughly cut down to the approximate size with a band saw. A mill will be used to make precise 45 degree angle cuts at the ends of the square tubes to they can fit together in the necessary configuration. The pieces will be TIG welded together to form the arms.

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Different parts of the rocker bogie arms will have different holes cut into them. The center bogie will have two ½” holes taped into both arms. The front and rear bogies will be mounted to these holes and pivot from them. The central bogie will also have twenty-eight 10-24 holes on the length of the arm. These will allow the central bogie mounting to be adjusted forward and backward from the chassis, allowing for adjustable ballasting. The front and rear bogies will have the ½” holes as well and three 10-24 holes both arms to secure the wheel assembly too. The three 10-24 holes are placed in a triangular formation around the ½” hole to prevent the wheel assembly from pivoting. All holes will be made on the mill.

The chassis will be laser cut from 1/8th inch thick sheet aluminum. The team has located a shop called Serra Laser Center equipped with laser cutting facilities capable of cutting aluminum. First the design and dimensions of each of the pieces will be drawn out in AutoCAD and exported as a DXF file. This file will be sent to Serra Laser Center and will be used to cut the pieces for the chassis. Once the cut pieces are obtained, some pieces will still require a few holes be made using the mill and assembly can take place. The holes will be sized for 1/8th inch screws.

The wheel assemblies will be constructed out of the same T-6061 aluminum as the body. There will be a total of six wheel assemblies each constructed in the following manner. A Servo bracket (L-bracket) will be mounted directly to each bogie arm using a ½ holes tapped through their centers. On the other face of the servo bracket, a 0.625” hole will be milled for the servo output shaft to run through. The servo itself will be mounted to three 10-24 holes. The servo output shaft will run to a second bracket, which will house the drive motor for the wheel. This will allows the servo to rotate the wheel for steering. The face of the second bracket, which is normal to the ground, will serve as the motor mount. The motor mount will have a 0.472” motor shaft hole milled into it. The motor shaft will run through it and the motor itself will be secured to the face of the motor shaft using twelve 10-24 holes arranged circularly around the motor output shaft. Each of these will be made with the mill. The output shaft will run to a wheel spindle.

The spindle will be machined from T-6061 aluminum bar stock on a lathe. The lathe will be used to make two cylinders on the bar. The first cylinder will have a length of 2” and a diameter of 0.750”. This cylinder face will have a 0.250” hole drilled into it using the lathe. This hole will be used to house the motor output shaft. The output shaft will be secured using two screws running through 0.0070” diameter holes milled into the top of the spindle. The other cylinder on the spindle will be 0.5” in length and have a 0.375” diameter. A 10-24 hole will be taped and threaded to secure the wheel hub onto.

The wheel hub will be made from T-6061 Aluminum. A cross shape will be made to fit within the 5.5” inner diameter of the wheel and will be 1” thick. 0.150”, 10-24 tapped holes will be milled into the arms of the cross such that they face the inner face of the wheel. Screws will be used to secure the hub to the wheel.

The wheels themselves will be made from 6” diameter, 0.5” thick aluminum tubing. They will be cut down to size on a band saw and will be machined on the mill using a rotating vice to cut straight lines every twelve degrees. The result will be a 30-sided triacontagon. Each face will be 0.950”. This design will provide more traction than a smooth circular face. 1” long flat faces will also be cut on the inside of the wheel in the same way. These will be used to mount the

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wheel hub to. 0.150” holes will be milled from the outside for the screws to run through, into the wheel hub.

Body Manufacturing Status

The bogie arms have been fully cut and milled, including the 45 degree cuts. They are ready for assembly. The AutoCAD drawings complete for the chassis and wheel assembly brackets so and have been sent to Serra Laser Center. Aluminum still needs to be purchased for cutting. The wheel spindles have been successfully machined, and wheel machining is in progress.

Body Assembly Plans

To assemble the bogie arms, the pieces will be bracketed into the correct formation using clamps and vises, so that they can be TIG welded together without becoming distorted. The chassis of the AGSE will be assembled in a similar manner with the use of L-brackets as well. Once the chassis and bogie arms have been assembled separately, the arms will be mounted onto using 10-24 screws and adjusted to ballast the body. The wheel assemblies will be assembled using 10-24 screws.

Body Assembly Status

Currently the team is waiting for the completion of the laser cutting and component fabrication of the chassis to be finished before assembly can begin. Fabrication for the bogie arms is partially complete and some assembly is in progress. The wheel assembly still requires fabrication.

Camera Subsystem

Camera Subsystem Manufacturing Plans

All of the components for the camera subsystem will be purchased and manufactured by their respective companies, thus no manufacturing plans are required for this subsystem.

Camera Subsystem Assembly Plans

The purchased parts will require some minor assembly. The Pixy Camera will be connected to the Arduino board using jumper wire and the servos for the pan tilt head connect directly to the Pixy Cam. Both parts will be mounted onto the pan tilt head, which will be assembled according to the provided instructions. The Arduino board will be powered by a Allpower 50k mAh power bank Once each component is assembled, programing may commence, so that the camera subsystem is fully operational.

Camera Subsystem Assembly Status

All of the necessary components for the AGSE camera subsystem have been purchased and obtained. Furthermore, each component of the camera subsystem is fully assembled and programing is in progress.

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Payload Retrieval Subsystem

Payload Retrieval Subsystem Manufacturing Plans and Status

The payload retrieval system only consists of purchased components and thus will not require any manufacturing. The fully manufactured pieces have been obtained ready for assembly.

Payload Retrieval Subsystem Assembly Plan

The Lynxmotion Al5D Robotic arm will require some extensive assembly. The C brackets for the arm will be mounted to each other using ¼” steel nuts screws and nuts. These will be mounted to the multi-purpose bracket on the base of the arm in a similar fashion. The HS-805BB servo will also be mounted to this base, with the servo horn connected to the C brackets. Two multi-purpose brackets will be attached to both ends of the provided aluminum tube via a pair of tubing connector hubs their own dedicated L-brackets. Each of these multi-brackets will have their own HS-755HB servos mounted to them to rotate the arm, and the wrist of the AL5D. A final C-bracket will be attached to the terminal end of the AL5D arm and the robotic wrist will be mounted to it. The robotic wrist has the gripper and an HS-422 servo built into it. Each servo will be connected to a Beaglebone Black board housed inside the chassis with jumper wire. The AL5D itself will be mounted to the front face of the chassis. Once the AL5D is assembled, the arm will be programed with the Beaglebone Black.

Payload Retrieval Subsystem Assembly Status

The AL5D has been fully assembled and is being tested and fine-tuned to reduce mechanical error. The software uses reverse kinematics to position the arm. The team has also just acquired the subsystems Beaglebone Black board, but testing for the components functionality using an Arduino Board prior to that acquisition. Further fine tuning, testing and programing is in progress.

Integration Plan

The AGSE integration plan consists of three phases: tactical, operational and analytical. Tactical refers to the manufacturing and construction of the AGSE. Operational refers to the time during which the AGSE operates autonomously. Analytical refers the any data analysis that takes place after the AGSE had competed its designated tasks.

Tactical (construction and manufacturing)

Body

Manufacturing details for the body and component integration for the body is fully detailed in the manufacturing plans.

Camera Subsystem

The camera subsystem will be directly mounted onto an aluminum mast. The mast itself will be formed from hollow aluminum round tubing and bolted to the chassis. The pan-tilt head will be mounted directly onto the top of the mast on a fabricated mounting plate that attaches

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directly to the top of the mast. The pan-tilt head will support the pixy camera itself, which will connect to the Arduino mounted onto the chassis through wires running inside of the aluminum tubing that comprises the mast. This Arduino Uno will be slaved to the master Arduino mega. It will relay data used to determine the location of target objects to the mega, which will be translated and relayed to the servos and motor controllers of the wheels.

Payload Retrieval

The robotic arm comes as a kit and only needs to be assembled according to the manufacturer's instructions. Once constructed, the arm will be mounted in the mouth of the AGSE chassis, as shown in Figure 62.

Main Computer /Power Supply

The main computer and power supply subsystem components will be mounted onto the chassis in the locations shown in the system overview diagrams section.

Operational

System Level

All AGSE subsystems will be connected to a master switch which will be connected to the master microcontroller. The master microcontroller will also be connected to a pause switch, which will function to halt all autonomous subroutines if toggled.

Subsystem Level

Body

Through the operational phase the suspension will be used to compensate for unevenness in the terrain. The two rocker arms on the side of the chassis will pivot independent of one another allowing for a height difference on both sides without an effect on the tilt of the chassis. This will prevent the chassis from tipping over and allow for the rover to travel on uneven terrain as would be expected in a Martian environment

Camera Subsystem

Throughout the operational phase the camera subsystem will repeat its subroutines to recalibrate the orientation of the AGSE with respect to the payload to ensure the proper trajectory.

Payload Retrieval

The payload retrieval subsystem will activate when the AGSE is within a 20 inch reach of the robotic arm. The data required will be retrieved from the Camera subsystem via the master microcontroller.

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Component Level Integration

Table 39 summarizes component level integration.

Table 39: Component Level Integration

Components How they Interface

Beaglebone Black / Robotic ArmArduino Mega will interface with the Robotic Arm and provide the arm with all of its controls using the I/O pins on the board.

Arduino Mega / Pixy Arduino Uno

The Arduino Mega will preside as the master controller over the edge and color detection system’s Arduino Uno. This Arduino Uno will receive commands from the Arduino Mega, and will process data from the edge and color detection system and send that data back to the Arduino Mega for further commands.

Pixy Camera / Arduino Uno

The Pixy Camera will perform the color and edge detection for the AGSE, and will process any data received from the Pixy Camera and relay the data back to the master controller.

Arduino Mega / Motor Controllers

The Arduino Mega will interface with the motor controllers and issue commands to the controllers pertaining to the movement of the AGSE. These commands will be determined from the data received from the slaved Arduino Uno units for the Pixy Camera and the LIDAR system. All four motor controllers will work together simultaneously to provide the steering and movement capabilities of the AGSE.

Front Left Motor Driver / Motors

The Front Left Motor Driver will connect to the front left drive motor and steering motor / servo. This motor driver will power the motors and be responsible for the front left wheel’s steering and navigation.

Front Right Motor Driver / Motors

The Front Right Motor Driver will connect to the front right drive motor and steering motor / servo. This motor driver will power the motors and be responsible for the front right wheel’s steering and navigation.

Back Left Motor Driver / Motors The Back Left Motor Driver will connect to

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the back left drive motor and steering motor / servo. This motor driver will power the motors and be responsible for the back left wheel’s steering and navigation.

Back Right Motor Driver / Motors

The Back Right Motor Driver will connect to the back right drive motor and steering motor / servo. This motor driver will power the motors and be responsible for the back right wheel’s steering and navigation.

Main Power Supply / Arduino Mega

The Main Power Supply will interface with the Arduino Mega and provide power to the Arduino Mega and all of its slaved Arduino Uno microcontrollers, as well as provide power to the Robotic Arm subsystem.

Power Supply / Motor Controllers

Each motor controller will have a dedicated power supply allocated to it, which will provide power to both the controller and the attached steering and drive motors.

Suspension / Motors

The motors will be mounted into the rocker-bogie suspension system. The drive motors will be connected to both the suspension system and the wheels, while the steering servos will be attached to a rotating portion of the wheel frame that will allow the AGSE to turn on a dime.

Motors / Wheels

The drive motors will be mounted into the framework of the suspension and attached to the wheels at the center of each wheel. This will provide the forward / backward motion of the wheels.

Robotic Arm / AGSE Chassis

The Robotic Arm will be bolted directly to the mouth of the chassis, and allowed to move freely via the servo motors that will control the arm.

Chassis / Pixy CameraThe Pixy Camera will be mounted onto a camera mast, which will be bolted to the chassis’ top.

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Suspension / Chassis

The rocker-bogie suspension system will be attached to the chassis via a single rod, and the back half of the rocker bogie suspension will be permanently attached to the chassis. The front bogie will be attached to the rear bogie (and not attached to the chassis), which will allow the suspension system to function as intended.

Analytical

A qualitative analysis of the entire AGSE system and its subsystems will be carried out to determine the success of the mission. No quantitative data will be available for analysis.

Precision of Instrumentation and Repeatability of Measurement

The only subsystems utilization any instrumentation equipment are the Camera Subsystem, and the Payload Retrieval Subsystem. Each subsystem and its measurement instrumentation is addressed in the following tables.

Table 40: Camera Subsystem Instrumentation Performance

Instrumentation Accuracy Repeatability Recovery

Camera Pan-Tilt Head

Experimentally Determined

Can be repeated with every launch

N/A

Table 41: Payload Retrieval subsystem Instrumentation Performance

Instrumentation Accuracy Repeatability Recovery

Servos ±0.1 deg Can be repeated with every launch

N/A

Camera Module Edge Detection

Can be repeated with every launch

N/A

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AGSE/ Payload electronics

Drawings and schematics

Figure 70: Overall AGSE Electrical Schematic

Block diagrams

The following block diagram (Figure 71) represents the various microcontrollers and major electronic components of the AGSE. The arrows represent data flow. The Arduino Mega functions as the master controller, sending commands to all other microcontrollers. All other microcontrollers also send data back to the master controller, allowing the master to determine when the slave controllers should or should not continue to run their respective algorithms. The Allpower 5V battery will power all the microcontrollers, and will be wired in parallel to allow for equal voltage distribution across all microcontrollers. The T-Rex modules will be powered by the multi-voltage Anker power bank, as the motors themselves will require 12 volts from the T-Rex modules to function properly. The Pixy Camera and Robotic Arm are expanded in their own individual block diagrams, shown below in Figure 72 and Figure 73.

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Figure 71: AGSE Overall Block Diagram

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Figure 72: Pixy Camera Block Diagram

Figure 73: Robotic Arm Block Diagram

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Batteries/power

The several microcontrollers of the AGSE will be powered by a single Allpower Lithium Polymer power bank, providing 5V of electricity and 50k mAh capacity when wired in parallel to all microcontrollers at once. This power bank can supply enough ampere-hours to run the AGSE control modules for several hours beyond the two hour recommendation stated in the Student Launch Handbook. This power bank has been removed from its frame and hardwired to bypass the control console that normally would allow the power bank to be used with USB. Figure 74 shows this power bank without the outer shell attached.

Figure 74: Allpower Power Bank

In the previous diagram, the manufacturer’s circuit board was bypassed by soldering wires directly onto the battery contacts. We then soldered solid 18 gauge jumper wire onto the circuit, which successfully powered the Arduino Uno board. As can be seen from the previous diagram, the supposed 5V battery actually only outputs 4.1 volts. This could be due to the battery itself, or due to the amount of capacity left in the battery when the test was done. The battery was not fully charged. To safely keep the voltage in the correct zone for microcontrollers (around 5 volts), an additional 1-volt lithium polymer battery will be wired in series to increase the maximum output voltage to 6 volts. As the battery drains, the voltage should remain safely within acceptable voltages of 4-6 volts. If additional ampere-hour capacity is required across the

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circuit, additional assemblies of batteries will be wired parallel into the circuit to provide the needed additional ampere-hours. Figure 75 and Figure 76 shows how two batteries with different mAh ratings can be combined to increase voltages as necessary without any harm to the batteries. In the figure, a 4.2 volt battery was wired in series with the 4.1 volt battery, which combined provided 8.3 volts of combined voltage as expected.

Figure 75: Single 4.2 Volt Battery Testing

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Figure 76: Series Circuit Using Both Batteries

The robotic arm contains a mega-servo that requires 6 volts, so the same technique will be used to power the robotic arm. The first choice is to use a 7-volt power supply to power the arm, but if one cannot be found that meets our requirements, we will wire 1-2 volt batteries in series with another Allpower 5V power bank. This power bank will be dedicated to the robotic arm’s servos.

The T-Rex motor controllers and motors will be powered by an Anker 26,000 mAh adjustable voltage lithium power bank. This power bank will be set to output the 12 volts required for the six 12 volt motors, which will be wired to the T-Rex to provide proper control over the voltage and ampere values output to the motors. This power bank will be pulled out of its aesthetic aluminum shell and hardwired in the same manner that the Allpower power bank is wired. Fuses for this power supply are built into the T-Rex controllers, and are resettable

Switch and indicator wattage and location

As required by the competition, the AGSE will have a Master Power Switch and a Pause Switch. Both switches are rated for up to 20 amps at 125 volts AC current. This means each switch is rated for up to 2500 watts. The indicator lights have not yet been chosen, but will be LED lights that draw very little current; approximately 10-20 mA. Therefore, the wattages for these, as they will be wired to at most a 19-volt power supply, will be very low. These switches will be located on the rear of the AGSE, and will each have their own indicator lights. The

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Master Power Switch will turn on and remain on, using a green LED, to indicate that the power is on for the AGSE. The Pause Switch will be yellow, and will blink when paused and remain solid when un-paused. See Figure 77 for a more detailed look at the location of the switches on the AGSE. See Figure 70 for the electrical schematic of the AGSE, showing in detail how all the components are interconnected and where the switches are located.

Figure 77: Master and Pause Switch Locations

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Test plans

The electrical components that are connected to the master and pause switches are described below in Table 42.

Table 42: Testing Plans for Safety Related AGSE ElectronicsComponent Requirement Testing Method

Master Power Switch Must cut or allow power to the entire AGSE.

A test circuit including an Arduino will be wired to the switch. The switch will then be tested to ensure that when the switch is off, the Arduino is off, and when the switch is on, the Arduino is on. Once this test is passed, the switch will be wired in parallel with all of the power supplies and tested in a similar fashion to ensure that the switch is capable of disabling power to the entire AGSE.

Pause Switch

Must pause all of the AGSE’s functionality, but allow the AGSE to remain fully powered on.

A test circuit including an Arduino Mega will be wired to the switch. The switch will then be tested to ensure that when the switch is in the off position, the Arduino is paused, and when the switch is in the on position, the Arduino is on. Once this test is passed, the switch will be wired in parallel with all of the power supplies and Arduinos in the applicable master-slave circuit and tested in a similar fashion to ensure that the switch is capable of pausing functionality in the entire AGSE at any point throughout its operation.

Master Power IndicatorMust illuminate when power is on and not be illuminated when power is off.

The LED will be wired with its respective switch and inspected to ensure that the light remains on while the switch is on and the light is off when the switch is off.

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Pause IndicatorMust blink when paused and remain solid and illuminated when un-paused.

The LED will be wired with its respective switch and inspected to ensure that the light is blinking at the required interval while the switch is on and the light is solid when the switch is off.


Table 43 shows the AGSE failure modes and the mitigations for those failure modes.

Table 43: AGSE Failure AnalysisRisk Consequence Pre-

RAC

Mitigation Pos-RAC

AGSE collides with launch rail

Launch rail is possibly damaged, knocked over, or rocket sustains damage

1C-9

Safety officer will be ready to hit the turn off button on the AGSE if it appears to be heading towards a collision

2C-5

AGSE collides with nearby objects

AGSE sustains damage from collision, object falls over obstructing path

1C-12


2C-5

AGSE circuitry sparks

Electrical system within AGSE body is destroyed, AGSE loses functionality

2B-16

Circuits will be continuously checked throughout assembly,

2B-12

AGSE power source malfunction

AGSE loses functionality 2B-16

Add additional battery assembly to maintain proper voltage

2B-12

Pivot bracket failure

Arm is unable to reach payload, Arm is unable to retreat upward once grabbing payload

1C-10

Pivot bracket will undergo rigorous testing to ensure functionality

1C-8

AGSE runs over feet

Injured foot/feet 1C-8


1C-6

AGSE collides with shins

Bruised shins 1C-8


1C-6

AGSE camera system follows spectator

AGSE fails to retrieve payload 2C-5

Safety officer will turn off the AGSE, reposition the device, then restart

2C-4

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AGSE/ Payload Concept Features and Definition

Creativity and Originality

The design of the AGSE chassis and framework is completely designed by the team from scratch. The only idea that will be taken from previous designs already in use is the rocker-bogie style of suspension system. However, the method by which the rocker-bogie suspension system will work will be designed from scratch by the team.

Uniqueness or Significance

The overall research goal of the competition is to research and develop innovative methods by which a payload may be recovered and delivered from another planet and back to Earth for analysis. This rover design is aimed to satisfy many of the concerns involved with designing such a device, including autonomously locating a payload, navigating to the payload, and delivering that payload back to the rocket for its trip back to Earth (or another location).

Suitable Level of Challenge

The designed AGSE has a sufficient level of challenge for a number of reasons. First, the programming required to make the entire AGSE function is vast, and provides a large amount of the challenge associated with the entire project. Second, the manufacturing of the AGSE contributes to the overall challenge, as members of the team much learn to machine and weld to the proper standards as would be required for the AGSE function properly.

Science Value

AGSE/ Payload Objectives and Success Criteria

The objective of the project is to research innovative methods by which an object might be recovered and loaded into a rocket autonomously. This research will prove useful when planning an interplanetary mission that requires a robotic device that will retrieve a payload (or set of payloads) and send them back to Earth for analysis. As such, the AGSE will be designed to accomplish a set of several scientific objectives that will generate data relevant to such a mission. These objectives and relevant success criteria are listed in Table 44.

Table 44: Scientific Objectives & Success Criteria

Objectives Success Criteria

Construct Autonomous Ground Support Equipment (AGSE) that can navigate autonomously to a payload and to the rocket.

The AGSE navigates to the payload and rocket in such a way that allows for a successful retrieval of the payload and insertion of the payload into the rocket payload bay.

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Program a purchased robotic arm to locate and acquire the payload and consequentially insert that payload into the rocket payload bay.

The robotic arm successfully retrieves the payload and inserts it into the rocket through the payload bay doors.

Design and build a payload bay that autonomously seals and houses the payload during all stages of flight (ascent, descent, landing, etc).

The payload doors seal autonomously after the payload is inserted, and the payload remains in the rocket safely, without damage, during flight and is found in such a way when the payload containment bay is retrieved by team members or other personnel.

Deploy the payload containment bay at approximately 1000 feet AGL.

The payload containment bay is successfully deployed within 50 feet of 1000 feet AGL without damage to the rocket or the payload containment bay.

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V. Project Plan

Status of Activities and Schedule

Budget Plan

Table 45: Budget

ItemPlanned Purchased

QuantityAmount

Each Total ShipQty.

OrderedUnit Price

Shipping Paid Total

6" rocket

6" x 48" Blue Tube 3 $66.95 $200.85 $0.00 0 $0.00 $0.00 $0.006" fiberglass nosecone (Model: FNC-6.0) 1 $99.95 $99.95 $13.95 0 $0.00 $0.00 $0.00

Nylon Shock Cord: 5/8", 5 yards, Presewn End Loops 2 $19.00 $38.00 $0.00 0 $0.00 $0.00 $0.00

54mm x 48" MMT Airframe Blue Tube 1 $23.95 $23.95 $0.00 0 $0.00 $0.00 $0.00

CNC fin slots (service fee) 6 $4.00 $24.00 $0.00 0 $0.00 $0.00 $0.00

96" elliptical parachute 1 $275.00 $275.00 $0.00 0 $0.00 $0.00 $0.00

Total: 14 $661.75 $13.95 0 $0.00 $0.00

Motor hardware/reloads

Aerotech K1100T-L reload Kit 1 $118.64 $118.64 $0.00 0 $0.00 $0.00 $0.00

54/1706 Motor Hardware Set (w/ Forward Seal Disc)

1 $196.88 $196.88 $0.00 0 $0.00 $0.00 $0.00

Total: 2 $315.52 $0.00 0 $0.00 $0.00

Fins

2' x 4' 1/4" finnish birch aircraft plywood for fins

1 $56.38 $56.38 $9.14 1 $45.88 $0.00 $50.01

Total: 1 $56.38 $9.14 1 $0.00 $50.01

Total Rocket: $1,460.64

4" rocket (subscale)

4" x 48" Blue Tube 2 $38.95 $77.90 1 $42.95 $1.26 $48.08

4" x 8" avionics bay 1 $41.95 $41.95 1 $41.95 $0.00 $45.7338mm x 48" MMT Airframe Blue Tube 1 $16.49 $16.49 1 $16.49 $16.49 $34.46

3.9" bulkhead w/ eyebolt 2 $4.29 $8.58 2 $4.29 $0.00 $9.35

3.9" to 38mm centering ring 3 $4.25 $12.75 $24.95 3 $4.25 $24.95 $38.85

3.9" plastic nosecone 1 $21.95 $21.95 1 $21.95 $0.00 $23.93

shock cord, 3 yd, 1/2" nylon tubular, presewn endloops

2 $14.00 $28.00 2 $14.00 $0.00 $30.52

24" Nylon Parachute 1 $9.29 $1.26 $11.39

30" elliptical parachute 2 $64.00 $128.00 2 $64.00 $0.00 $139.5248" Fruity Chutes Classical Elliptical Parachute 1 $113.42 $1.26 $124.89

24" Drogue Chute (FruityChutes) 1 $62.06 $1.26 $68.91

Madcow 12" Chute Protector 3 $8.51 $1.26 $29.09

18" elliptical drogue 3 $51.00 $153.00 $17.00 3 $51.00 $0.00 $166.77

Altimeter Mounting posts 3 $3.50 $1.26 $12.71

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1/4" Quick Link 8 $3.75 $1.26 $33.96

Rail Buttons 2 $3.07 $1.26 $7.95

Aerotech I161W-M reload 1 $37.79 $37.79 1 $37.79 $0.00 $41.19

Nylon Sheer Pins 2 $2.95 $1.26 $7.69

Electronics Rotary Switch 3 $8.22 $1.26 $28.14

09132 Electronics Mounting Kit 1 $40.00 $1.26 $44.86

38/360 Motor Hardware Set 1 $114.61 $114.61 $60.83 1 $114.61 $0.00 $124.92

Total: 19 $641.02 $102.78 43 $55.33 $1,072.92

AvionicsMissile Works RRC2+ Sport Altimeter 2 $69.95 $139.90 $6.10 4 $44.95 $6.10 $202.08

Altus Metrum TeleGPS 1 $214.00 $214.00 $8.37 1 $214.00 $8.37 $241.63

Nuts / Bolts / Hardware 1 $50.00 1 $21.66 $0.00 $23.61

Total: 4 $403.90 $14.47 6 $14.47 $443.71

Robotic Arm

AL5D Robotic Arm Combo Kit 1 $309.81 $309.81 $0.00 1 $309.81 $0.00 $309.81Beaglebone Black Microcontroller 1 $79.95 $79.95 $0.00 1 $79.95 $0.00 $79.95

Total: 2 $389.76 $0.00 2 $0.00 $389.76

Payload Compartment

Arduino Uno 1 $24.95 $24.95 $0.00 1 $24.95 $0.00 $27.20

EM506 GPS 1 $39.95 $39.95 $0.00 0 $0.00 $0.00 $0.00

GPS Shield 1 $14.95 $14.95 $0.00 0 $0.00 $0.00 $0.00

Xbee Pro 900 2 $54.95 $109.90 $0.00 0 $54.95 $0.00 $0.00

Antenna 2 $7.95 $15.90 $0.00 0 $0.00 $0.00 $0.00

Power Source 1 $19.99 $19.99 $0.00 0 $0.00 $0.00 $0.00

Spring-Loaded Hinge 2 $3.38 $6.76 $0.00 0 $0.00 $0.00 $0.00

Total: 10 $232.40 $0.00 1 $0.00 $27.20

Navigation Package

Arduino Uno 2 $24.95 $49.90 $9.47 3 $24.95 $0.00 $81.59

Pixy Camera Module 1 $69.00 $69.00 $0.00 2 $69.95 $0.00 $152.49

Pan-Tilt Head 1 $39.00 $39.00 $0.00 1 $39.95 $0.00 $43.55

Total: 4 $157.90 $9.47 6 $0.00 $277.62

AGSE Structural ComponentsPack of 30 ball bearings 1 $17.82 $17.82 $0.00 1 $5.99 $0.00 $6.53

2" x 3" x 1/8", 8-ft long aluminum rectangular Tubing (6061-T6) 1

$52.26 $52.26 $52.80 0 $0.00 $0.00 $0.00

1" x 1" x 1/4" 12-ft long aluminum Square Tubing (6061-T6)

1 $31.13 $0.00 $33.93

Aluminum Sheet Metal 6061-T6 (36" x 48" sheet) 2 $133.35 $266.70 $0.00 0 $0.00 $0.00 $0.00

Nuts, bolts, and washers 1 $50.00 $0.00 0 $0.00 $0.00 $0.00

1" Inner Diameter 6061-T6 Aluminum Rod 1

$22.42 $22.42 $0.00 1 $40.50 $0.00 $44.15

6" Diameter Hollow 6061-T6 Tubing (Wheels) 1 $131.50 $0.00 $143.34

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12V 200 RPM DC Motor 6 $11.95 $71.70 $20.00 4 $9.95 $0.00 $43.38

Anker Astro Pro 20Ah Lithium Battery Pack 1 $88.49 $88.49 $0.00 1 $88.49 $0.00 $96.45

Total: 13 $569.39 $72.80 9 $0.00 $367.78

AGSE Controller ComponentsArduino Mega 1 $49.95 $49.95 $0.00 1 $49.95 $0.00 $54.45T-Rex Motor Driver 5 $74.95 $374.75 $0.00 2 $74.95 $0.00 $149.90

Total: 6 $424.70 $0.00 3 $0.00 $204.35

Launch Competition

Airfare (6 x 400) $2,400.00 $0.00

Hotel (3 x 3 x 150) $900.00 $796.88

Rental Van (1 x 200) $400.00 $0.00

Food and Entertainment $500.00 $0.00

Freight $400.00 $0.00

Total Launch Competition: $4,600.00 $796.88

Outreach $3,500.00 $2425.50

Projected Launch Pad Total: $3,620.32

Current Launch Pad Total $1,760.42

Projected Total: $12,175.33

$1,460.64

$743.80

$389.76$232.40

$167.37

$642.19

$424.70

$4,600.00

$3,500.00

Planned Budget Distribution

RocketSubscale RocketRobotic ArmPayload CompartmentNavigation PackageAGSE Structural ComponentsAGSE Controller ComponentsCompetitionOutreach

Figure 78: Planned Budget Distribution

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Funding Plan

Table 46: Funding Plan

Activity Funded by Amount Funds used for

Junior Rocket Owls Program

Citrus College Foundation / Private Donors

$8,000.00

$6, 000.00 to sponsor the Citrus Rocket Owls’ participation in the NASA Student launch and $2,000.00 to purchase supplies for the Junior Rocket Owls activities

Azusa STEM Pathways

Canyon City Foundation $6,500.00

$5,000.00 to sponsor the Citrus Rocket Owls’ participation in the NASA Student launch and $1,500.00 to purchase supplies for the STEM Pathways activities

Science and Technology Fundraiser Event

Citrus College in collaboration with local businesses

$2,000.00Sponsor the Citrus Rocket Owls’ participation in the NASA Student launch

Night on the Plaza Fundraising Event

Glendora Public Library Foundation $200.00

Sponsor the Citrus Rocket Owls’ participation in the NASA Student launch

Presentation to the RACE to STEM committee members

RACE to STEM Title V Grant $500.00


KIWANIS Club Presentation KIWANIS Club $500.00


Solicitations to local businesses Private donations $2,000.00


Total:

$19,700.00

Sponsor the Citrus Rocket Owls’ participation in the NASA Student launch and their educational engagement activities

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Timeline

Below are the timelines for the different aspects of the project. The first timeline outlines the dates for the NASA SLP project. The report deadlines and other important dates are given. The second timeline outlines the construction and testing dates for the AGSE and launch vehicle. The third timeline gives the educational engagement dates.

Figure 79: NASA Student Launch Timeline

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Figure 80: AGSE and Rocket Construction Timeline

Figure 81: Outreach Timeline

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Educational Engagement

The Rocket Owls are involved in a multitude of educational activities in the communities served by Citrus College, including Azusa and Glendora. These activities consist of: year-long projects, classroom presentations, booth presentations, and weekend workshops. A brief description of these activities is introduced next, followed by a sketch of the evaluation methods of those activities.

Year-long Projects

The two year-long outreach projects organized and conducted by the team are: the Junior Rocket Owls Program and STEM Pathways. They are briefly described below. The Junior Rocket Owls Project gives the Citrus Rocket Owls a unique opportunity to act as mentors for 5th grade students, while providing them with the opportunity to participate in a year-long project geared towards enhancing their knowledge of and interest in science, mathematics and engineering. Students enrolled in 5th grade at La Fetra School in the Glendora Unified School District (GUSD) work in teams under the facilitative leadership of the Citrus Rocket Owls to design, build and launch simple model rockets and compare their performance to predictions made in advance using rocket simulation computer software. They apply physics principles to predict the performance of a model rocket and use mathematical models to analyze their data. The Junior Rocket Owls have had their first monthly meetings with their college mentors on July 12 and August 9, 2014. The meetings will continue on a monthly basis throughout the 2014-15 academic year. Detailed information about this program can be found on the Junior Rocket Owls website at: http://www.citruscollege.edu/academics/owls/jr/ The Rocket Owls involvement in the Azusa Unified School District (AUSD) science, technology, engineering and math (STEM) Pathways Program consists of the team members working with students and teachers from Slauson Middle School on rocketry-related activities on a monthly basis. The Rocket Owls will meet with 6th, 7th, and 8th grade students and their teachers to facilitate workshops that they have designed in advance. All workshops’ activities will consist of hands-on scientific inquiry and engineering design activities. AUSD students will work in teams under the facilitative leadership of the Citrus Rocket Owls to address the scientific inquiry questions with simple experiments, followed by designing and building a model rocket, given a problem and a set of constraints. The activities will start with a pre-designing investigation, when students are asked to describe the experimental variables (dependent, independent, controlled) and end with a thorough analysis of the facts discovered. In addition, students will be required to draw diagrams of their designs, list the investigation procedural steps and collect and present the data in support of their investigation. Furthermore, students will prepare professional posters showcasing their work and present them to other AUSD students and teachers, as well as Citrus students and faculty.

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Classroom Presentations

In an effort to reach students with different learning styles, the Rocket Owls will conduct classroom presentations in a variety of forms to science classes at Citrus College and K-12 classes from the GUSD and AUSD. A PowerPoint will contain general rocketry information as well as a brief overview of the NASA Student Launch Competition for visual learners. The team will present audibly for those who learn by listening and will also ask questions covered in the PowerPoint to check for comprehension. For students who learn kinesthetically, the Rocket Owls will facilitate hands-on activities focused on the concepts discussed during the presentation. The planned hands-on activities are low cost. They include building and launching straw rockets and seltzer activated rockets. The team also plans to incorporate math and physics concepts by asking participants to solve simple rocketry problems at the end of the presentation. To encourage participation, small prizes will be awarded to those who solve the problems correctly.

Booth Presentations

The Rocket Owls are committed to spreading their passion for STEM and rocketry to the community by hosting information/activities booths at local events, including the Azusa 8th Grade Majors Fair, Glendora Public Library monthly science events, and Citrus College Physics Festival. These booths will give the community and students a chance to ask questions pertaining to rocketry, as well as NASA and its educational programs. The booths will also contain an activity tailored to the participants along with a worksheet explaining the main rocketry principles.

Weekend Workshops

The Rocket Owls plan to facilitate several weekend workshops where participants will work in small groups to conduct experiments related to rocketry. The main goal of these workshops is to introduce elementary and middle school students enrolled in GATE (Gifted & Talented Education) Programs in Glendora and Temple City to new ways of looking at science and mathematics, typically not seen in regular classroom environments. Each workshop will begin with a detailed presentation on the importance of safety procedures when building and launching a rocket. The safety presentation will be followed by an interactive discussion on basic rocketry principles, and will include steps for the construction of the rocket. During a short break, the Rocket Owls will introduce their goals for the NASA Student Launch Competition, along with the strategies for meeting those goals. The workshops will typically end with students launching the rockets that they built. Before launch, the Rocket Owls will ask the participants to predict the behavior of their rocket, followed by an after-launch discussion comparing their hypotheses to the actual rocket’s behavior. Two such workshops have already been planned by the team for the months of October, 2014 (Temple City workshop) and February, 2015 (Glendora workshop).

Evaluation

The goal of evaluating the Rocket Owls’ educational engagement program is to find the program’s impacts on the community, including elementary and middle school students, as well as community college students and other participants. The evaluation plan includes quantitative and qualitative methods. Both these methods will be used to examine the degree to which the

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Rocket Owls’ educational engagement program enhances the awareness and interest in STEM, rocketry, and NASA activities, throughout the K-12 local school districts and the community.

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VI. Conclusion

Project scension’s mission is to retrieve a 4 oz. cylindrical payload from the ground, launch it to an altitude of 3000 ft AGL, and eject the payload at 1000 ft AGL to be recovered separately from the rest of the launch vehicle. The payload will be identified and retrieved autonomously by a six-wheeled rover using a camera navigation system and a robotic arm. The rover will navigate autonomously to the launch vehicle and insert the payload through spring-loaded doors into the payload bay of the vehicle. Team personnel will manually move the launch vehicle to a vertical launch position, install the igniter, and clear the area for launch. The 20 lb, 6” diameter, 112” long launch vehicle will be powered by an AeroTech K1275R motor to an altitude of 3000 ft AGL. Upon descent, the payload bay will be ejected at 1000 ft AGL and descend under its own parachute. GPS tracking units will facilitate recovery of the launch vehicle and payload.

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Appendix A: Citrus College Profile

Since 1967, Citrus College has been providing a quality educational experience for the communities of Azusa, Glendora, Duarte, Claremont and Monrovia. It is currently home to over 12,000 students, the majority of whom are considered ethnic minorities, and is dedicated to creating a diverse and welcoming learning environment that supports educational achievement for all its students.

Citrus College offers many programs that promote community awareness in numerous STEM (Science, Technology, Engineering, and Mathematics) related fields. Biological and Physical Sciences is the second most common major in the school. There are also numerous extracurricular programs aimed at increasing interest in STEM subjects within the community, such as the SIGMA (Support and Inspire to Gain Motivation and Achievement) peer mentor program; the PAGE (Pre-Algebra, Algebra, Geometry Enrichment) summer K-12 mathematics enrichment program; and the Secrets of Science Summer Camp that provides K-12 students with practical experience in biology, chemistry, astronomy and physics laboratories.

Students at Citrus College are active participants in many STEM-related activities. In past years, students have participated in NASA’s Reduced Gravity Education Flight Program (RGEFP), have launched a near-space sounding balloon, and have also traveled to Huntsville, Alabama and to Salt Lake City, Utah as participants in the 2013 and 2014 USLI SLP (University Student Launch Initiative Student Launch Projects).

We hope to duplicate, if not supersede, the previous years’ successes with our own 2015 Student Launch project.

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Documents

Citrus College - NASA SL Criticla Design Review