Tokyo Tech Nano-Satellite CUTE-1.7 + APD Flight

Operation Results and the Succeeding Satellite

Jun. 28

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Ken Fujiwara, Kuniyuki Omagari, Thomas Iljic, Shinji Masumoto, Yasumi Konda, Tomio Yamanaka, Yohei Tanaka, Masaki Maeno, Taihei Ueno, Hiroki Ashida, Junichi Nishida, Yusuke Hagiwara, Kota Fujihashi, Takuro Ikeda, Shinichi Inagawa, Yoshiyuki Miura, Saburo Matunaga

Tokyo Institute of Technology, Laboratory for Space Systems

Introduction

2003.62003.6 TokyoTech CUTE-I Launch

CubeSat Project (10cm cubed picoCubeSat Project (10cm cubed pico--satellite)satellite)

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20042004～～

Plesetsk RussiaCUTE-I 10cm cubed, 1kg weight

- Acquisition of satellite bus technologies

CUTE-I

1. New design methodology

� Very low-cost development

� Short-term development

� Intensive use of COTS components

2. Share orbital demonstration opportunities

� Providing universal connectivity to the satellite

Tokyo Tech 2Tokyo Tech 2ndnd satellitesatelliteCuteCute--1.71.7

Contents

Cute-1.7 + APD:

– Development

• Missions

• Subsystems

– Flight Report

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– Flight Report

• Accomplished missions

• Encountered troubles

Cute-1.7 + APD #2:

– Modification

• Missions and Design

– Launch information

• Vehicle, date

Missions

1. Satellite bus development using COTS devices

2. Attitude control experiment

3. Amateur radio service

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3. Amateur radio service

4. Tether deployment experiment

5. APD sensor demonstration

6. Nano-satellite Separation System demonstration

PDA-based OBC

COTS-based PDA as the main computer:

• Advantages to accelerate the development

– High computing performance

– Easy software development

– Many external interfaces

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– Many external interfaces

– Availability and low price

• Drawbacks of COTS devices

– Radiation tolerance

– Reliability

Hitachi PDA NPD-20JWLUS

B

CF

slo

t

SD

slo

t

DAQ, COMM

Camera, 1-wire I/F, APD,

SD Card (Data Storage)

Radiation test

Redundant use of two PDAs

Communication Devices

• COTS-based handheld transceivers

– Small though High performance

– Easy to use, available at low-cost

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• Communication channels

– 144MHz AFSK/GMSK for uplink

– 1200MHz GMSK for amateur service

– 430MHz AFSK/GMSK for downlink

– 430MHz CW for beacon

Attitude control mission

Spin upLow speed rotation

3-axes stability

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Low speed rotation

& earth pointing

Uplink : new control

methods

Initially :

No control

Uplink :control

method selection

Attitude determination and control system

• Attitude Sensors– Sun sensor: 5 planes (photodiodes)

– Gyro sensor: 3 axis

– Magnetic sensor: 3 axis

• Attitude determination algorithms– Geometrical

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– Geometrical

– REQUEST

• Actuator– Magnet torquer (0.037Am2): 3 axis

• Control algorithms– B-dot

• Camera – CMOS camera: 320x256 pixel

Tether Deployment Mission

Objective of this mission : fundamental tether deployment for future missions

By cutting the

nylon thread

holding a plate

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Initial velocity from the push-

out springs : 30cm/sec

(data obtained from micro

gravity experiment at MGLAB,

Japan)

10m copper tether Deployment detection by

sensors and camera

Objective: experiment and demonstrate a new Avalanche Photo Diodesensor to detect charged particles on orbit.

APD Mission (Science)

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APD by Tokyo Tech astronomy lab.

APD

Measures Low-E(E>3 kev) charged particles distributionsin SAA and aurora band

System Block Diagram

PDAPDA

Deploya-

SW

Power Distribution Circuit

SW Memory

Card

5.0V

3.3V

Li+ Bat

カメラカメラカメラカメラHeater

Other

Devices

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Data Acquisition

System

USB HUB

Magnetic

Sensor

Gyro

Sensor

Magnetic

Torquers

Sun

Sensor

Deploya-

bles

Satellite

DisposalUSB⇔⇔⇔⇔

RS232C

FM430

Tx

FM1200

Rx

FM144

Rx

CW430

Beacon

Communication System Controller

Solar

Arrays

WDTカメラカメラカメラカメラ

CameraHeater

Dosim-

eters

Components Allocation

Battery

Monopole Antenna

（4）

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ＡＰＤ

Unit

EPS Board

Comm. Board

Comm. Radio Box

ＰＤＡ（２）

Magnetic

Torquers（３）

Sun Sensor（５）

ＤＡＱ,USB Hub,

Sensor Board, PDA SW

APD board

Battery

Magnetic Torquers

Control Board

（ ）

Specification

• Satellite

– Size：226x112x133mm

– Weight：3.6kg

– Power：3W

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• Separation mechanism

– Weight：2.5kg

– Deployment speed：0.3-0.6m/s

– Attitude disturbance：max. 0.4rad/s

Cute-1.7 + APD launch opportunity

Cute-1.7 + APD was launched as a subpayload on Feb 22, 2006 from the

Uchinoura Space Center (JAXA) in Kagoshima Prefecture.

The launcher was the JAXA M-V-#8.

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Cute-1.7 Telemetry Reception

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2006/4/23：：：：104 GSs- Japan: 40 stations- Foreign: 64 stations

OSCAR Number

10/3/2006 : CUTE-I, Cute-1.7 + APD got OSCAR-numbers

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CUBESAT-OSCAR-56(CO-56)Cute-1.7 + APD

(Feb. 22, 2006 launched)

CUBESAT-OSCAR-55(CO-55)CUTE-I

(Jun. 30, 2003 launched)

Over 1000 days operational

0.2ωx

ωy

An

gu

lar

Vel

oci

ty (

rad/s

)

Attitude Determination : Raw Gyro Data

Gyro data:

• Largest rotation about X axis

• Angular velocity, 0.28 rad/s

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-0.4

-0.2

0

0 50 100 150 200

ωy

ωz

An

gu

lar

Vel

oci

ty (

rad/s

)

Time (seconds)

XY

Z

Sun sensor data

The sun sensor data also showed the rotation about x axis. The

time cycle was about 30 seconds that correspond to gyro data

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Y

Z

Conducted missions and encountered problem

• Demonstration of PDAs as onboard computer

• Amateur radio cooperation

• Attitude sensor data acquisition

• Nano-satellite Separation System demonstration

EPS Battery Voltage

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2.5

3

3.5

4

4.5

5

2/14 2/24 3/6 3/16 3/26 4/5 4/15 4/25 5/5

EPS Battery VoltageEPS Main Bus Voltage

EP

S V

olt

age

Date

After 2 months operation:

• No reception to uplink command

• Increasing power consumption

• Radiation effect on communication

controller MPUDecreasing battery voltage

Cute-1.7 + APD #2 Project Outline

• Cute-1.7 + APD #1

– Transmitting non-modulated continuous wave

– Continuing recovery operation

• Cute-1.7 + APD #2

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– Conducting same missions except tether deployment

• Use of PDAs

• Attitude control

• Amateur radio service

• APD sensor demonstration

• Separation mechanism demonstration

– Using basically same bus components

– Applying some modifications to the 1st design

Modification: Radiation tolerant circuit

• Distributed auto-power reset functions

– Detect slight current increase caused by SEL

– Automatically restart unusual componentsAuto-power reset function

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Auto-

power

resetBattery EPS

SubsystemsAuto-

power

reset

Auto-

power

reset

Auto-

power

reset

Battery SW EPSCurrent Monitor Subsystems

Auto-reset signal

Cute-1.7 + APD #1 EPS system

Cute-1.7 + APD #2 EPS system

• Attitude determination algorithm– QUEST

– REQUEST

– Extended Kalman Filter (newly implemented)

• Attitude control algorithm

Modification: ADCS

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• Attitude control algorithm– B-dot

– Quaternion feedback (newly implemented)

• Magnetic torquer– Enhanced (tripled) magnetic dipole 0.112 [Am2]

• Camera– Increased resolution (640x480pixel)

Modification: Structure

• Size up

– 115x180x220mm

– Power generation increase

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• Simplified assembling procedure

• Frequent mission operation

Components Allocation

Battery

Magnet Torquers

Control Unit

DAQ, USBHub,

Sensor Unit

Comm. Control Unit CMOS Camera Unit

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Monopole Antenna (4)

Comm. Radio Box

EPS Control Unit

Sun Sensor (5)APD Sensor Unit

PDA (2)

Launch information

• Rocket– ISRO PSLV

• Orbit– Altitude: 635km, Sun synchronous

– Inclination: 97.89 deg

• Satellites:Oceansat 2 (India) -Main payload

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Oceansat 2 (India) -Main payload

AAUSAT II (Aalborg University)

CanX-2 (University of Tronto)

COMPASS-1 (University of Aachen)

Cute-1.7 + APD II (Tokyo Tech)

Delfi-C3 (Technical University of Delft)

SEEDS (Nihon University)

• Launch date– September, 2007 or later

From http://www.isro.org/pslv.htm

Summary

• Cute-1.7 + APD #1

– Developed to demonstrate a new design methodology

– Launched on Feb. 22, 2006

– Conducted part of its missions

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– Encountered SEL problem

• Cute-1.7 + APD #2

– Enhanced model of the first satellite

– Planned to be launched soon

Cute-1.7 + APD #2 project webpage:

http://lss.mes.titech.ac.jp/ssp/cute1.7/index.php

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Contact:

fujiwara@lss.mes.titech.ac.jp

Thank you !

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Development schedule

Apr. Design review

May Radio tolerance test

Jul. Integration test

Aug. Vibration test 1

Nov. Vibration test 2

Dec. Thermal test

2006

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Dec. Thermal test

Jan. Vibration test 3

Feb. Vacuum test

Apr. Sensor calibration

May Interface test at VSSC, India

Jun. Long-term operation test (3 weeks)

Jul. Residual magnetic flux measurement

2007

Gyro data: Quaternion form

These results have shown that :

-The x axis has the largest rotation

- The average angular velocity is of 0.28[rad/s]

1 q1q2

q3q4

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-1

-0.5

0

0.5

0 50 100 150 200

q2 q4

Quate

rnio

n

Time (seconds)

XY

Z