Reentry Demonstration Plan of Flare-type Membrane …gd.isas.jaxa.jp/~kzyamada/MAAC/2011/publication/2011...AIAA ADS Conference 2011 in Dublin 1 MAAC / Membrane Aeroshell for Atmospheric-entry

AIAA ADS Conference 2011 in Dublin 1

MAAC / Membrane Aeroshell for Atmospheric-entry Capsule 2011/05/24

Reentry Demonstration Plan of Flare-type Membrane Aeroshellfor Atmospheric Entry Vehicleusing a Sounding Rocket

Kazuhiko Yamada, Takashi Abe (JAXA/ISAS)Kojiro Suzuki (The University of Tokyo)Osamu Imamura (Nihon University)Daisuke Akita (Tokyo Institute of Technology)MAAC R&D Group

2MAAC / Membrane Aeroshell for Atmospheric-entry Capsule

2011/05/24

Contents

BackgroundLow ballistic coefficient atmospheric entry systemOur past research

Reentry demonstration plan using sounding rocket OverviewExperimental vehicle.Flight sequenceMeasurement items

Development status of aeroshell

Summary


2011/05/24

BackgroundRecently, the space activities become various and active more and more in Japan

Regular experiments in KIBO in ISS Operation of many small satellites (CANCSAT) Proposal of planetary exploration

HAYABUSA reentry

To support these space activities,the frequent, reliable and low-cost space transportation systembetween space and planet surface is necessary

Strong requirement for reentry and atmospheric entry system

It is importation that we have some options of reentry system to expand the possibility of human space activity and the planetary exploration mission besides the conventional system like the ablator system.


2011/05/24

Low ballistic coefficient atmospheric-entry system

Various concept has been proposed and developed since 1960’Towed torus, balloon, Attached ballute, Conical ballute…..

One of the candidate to innovate the atmospheric entry is Low-ballistic-coefficient atmospheric-entry system using flexible aeroshell

What is advantage of this concept?


2011/05/24

Aeroshell effect on the aerodynamic heating

Vehicle mass 100kg

Capsule diameter 1m

Curvature radius 0.71m

Aeroshell diameter Varied as parameter

Flare Angle 45deg

Drag Coefficient 1.3

Lift Coefficient 0.0

Initial velocity 7668m/s

Initial Altitude 400km

Initial flight pass angle 3.0 deg

Surface emissivity 0.8

Planet to entry EARTH

5m-diameteraeroshell

Withoutaeroshell

Assumed re-entry mission

Heat flux estimation: Tauber’s and Lees eq.

Aerodynamic heating reduction effects is clarified by simple trajectory simulation for a virtual assumed reentry mission.

stagnation

Aeroshell

Equilibrium T vs Aeroshell diameter


2011/05/24

Flare type membrane aeroshell Our group focus on

the flare type membrane aeroshell supported by an inflatable torus

This concepts have a lot of merits, but it have not been applied to actual mission until now

Uncertainty of dynamics and characteristics of flexible aeroshell


2011/05/24

Past Research

2000- Fundamental research and development startsex. Supersonic wind tunnel and numerical simulation

2004 Flight test using a balloonFlight demonstration of vehicle with flare type membrane aeroshell

2008- Hypersonic wind tunnel test starts

2009 Deployment and flight test using balloonDeployment and flight demonstration of inflatable aeroshell

2011, next milestone is

Reentry demonstration using a sounding rocket


2011/05/24

Next milestone of developmentThe experiment is carried out using a S-310 sounding rocket of ISAS/JAXA.

S310-rocket of ISAS

S-310 Rocket specification

Length : 7.1mDiameter : 0.31mPayload : 50kgMaximum Altitude : 150km

In this test, the experimental vehicle which has 20kg total mass including flexible aeroshell, reenter atmosphere from 150km in altitude.

<Main Objectives>

• To demonstrate the performance of the flare-type membrane aeroshell sustained by the inflatable torus as a decelerator in an atmospheric entry condition.

• To demonstrate the deployment of the inflatable aeroshell.• To acquire the aerodynamic characteristics and aerodynamic heating of the

vehicle.


2011/05/24

Experimental Vehicle

Space to pack the aeroshell

Capsule (Main body)Hemispherical head and cuboidal body.Diameter :228mm, Length : 510mm, Mass :15kg All of the electrical device and gas injection system are installed

Thin membrane flareMade of ZYLON textile.

Flare angle : 70 deg, outer diameter 100cm, Mass : 0.5kg

Inflatable torus frame Made of Silicon rubber and ZYLON textile Torus tube diameter : 10cm, Tours outer diameter : 120cm, Mass : 2kg

Inflated by gas injecting system, inner pressure is 135kPaA.

Aeroshell cover


2011/05/24

Test sequence

1. Aeroshell is packed around the capsule when launching

2. Nose cone opens after rocket engine burn out.

3. When aeroshell cover is released and gas is injected into the torus, The aeroshell was deployed.

4. Experimental vehicle was ejected from rocket.

7. At altitude about 55kmMaximum Mach number: 4.45Maximum heat flux: 18.6kW/m2

Maximum dynamic pressure: 0.66kPa

8. Vehicle splashes down with 16.8m/s in 1015 sec after top of trajectory. The vehicle floats on the sea with buoyant force of inflatable torus.

1Hz

Separation mechanisms

Reentry direction

6. Aeroshell shape and vehicle attitude become stable by aerodynamic force.

5. Experimental vehicle reenter to atmosphere with large angle of attack.


2011/05/24

Flight trajectoryVehicle mass : 20kg, Aeroshell diameter : 1.2m, Drag coefficient :1.5 – 1.0Initial Condition : Top of trajectory (Altitude 150km, Horizontal velocity 600m/s)

<Altitude and velocity> <Heat flux and dynamic pressure>

The vehicle accelerates to Mach number 4.45 in 134 seconds due to the gravity force.The vehicle decelerate due to aerodynamic force in altitude from 60km to 30 kmThe maximum heat flux and the dynamic pressure is 18.6kW/m2 and 0.66kPa, respectively.The vehicle splashdown with the terminal velocity in 16.8m/s.


2011/05/24

Measurement items and onboard sensors Aeroshell image

4 CCD cameras

Flight trajectoryGPS data.Pressure altimeter.Rader tracking.

Attitude and motion3D motion sensors (Accelerometer, angle velocity sensors, magnetic field sensor)5 Pressure sensors on the capsule to measure the pressure distribution.

Aerodynamic heating conditionThermocouples to measure temperature on the aeroshell

Inflatable pressureTiny pressure sensors embedded on the torus.

All flight data are transmitted to the ground station with telemetry system during flight, because the experimental vehicle is not recovered in this test.

Aeroshell image.


2011/05/24

Device arrangement All electric device and gas injection system is arranged in the capsule.

Capsule and onboard device is being developed now…


2011/05/24

Development status of Aeroshell

Determination of flare angle. Durability against aerodynamic heating.


2011/05/24

Determination of flare angle

Flare angle have a significant impact on the flowfield and aerodynamic heating

Flexible aeroshell model in hypersonic flow (Mach=9.45)

Flare angle = 45deg

Flare angle = 60deg

• Shockwaves interacts on the aeroshell.

• Flow field oscillates

• There is only bow shock• Flowfield is quite stable.

The results suggests that the flare angle have to be more than 60 degrees.

Local peak heating


2011/05/24

Durability against aerodynamic heatingThe durability of inflatable structure against aerodynamic heating was investigated using hypersonic wind tunnel and spherical inflatable model.

Test model mounted in hypersonic wind tunnel

Stagnation temperature and inner pressure history in blowing

The inflatable model did not rapture and was intact, though the surface temperature reached 450 degC.


2011/05/24

Summary

The flight test is planned to carry out in December 2011 at earliest.

The reentry demonstration using a S310 sounding rocket is planedand prepared. It is a important milestone of the development of the flare-type membrane aeroshell sustained by the inflatable torus for atmospheric entry vehicles.

So, the experimental vehicle is being developed with hard work, now


2011/05/24

Fin

Documents

Reentry Demonstration Plan of Flare-type Membrane …gd.isas.jaxa.jp/~kzyamada/MAAC/2011/publication/2011...AIAA ADS Conference 2011 in Dublin 1 MAAC / Membrane Aeroshell for Atmospheric-entry