flight experiment of the capsule with the deployable flexible aeroshell

2005/10/20 in Fukuoka

56th International Astronautical Congress IAC-05-D2.6.05

Flight Experiment of the Capsule with the Deployable Flexible Aeroshell

Using a Large Scientific Balloon

Kazuhiko Yamada, Daisuke Akita, Eiiji Sato,Kojiro Suzuki (University of Tokyo)Yuuki Tsutusmi, Kazuhiko Wakatuki (Tokai University)

Tomohiro Narumi, Akira Sakurai (Kyushu University)Takashi Abe, Yukihiko Matsusaka (ISAS/JAXA)

56th International Astronautical CongreeIn Fukuoka JAPAN



CONTENTS

BackgroundMembrane Aeroshell Concept

Outline of flight test Flight model

ConfigurationSensors

Results Behavior of membrane aeroshellFlight trajectoryAerodynamic Characteristics

Conclusions



BackgroundNew Concept of Atmospheric-entry system

Withstandhigh aerodynamic heating

Conventional Flexible Aeroshell

Avoidhigh aerodynamic heating

C/C material or Ablator

Parachute Systemfor Soft Landing

Large and Light Aeroshell

And Soft Landing



Outline of project

Drop flight test of actual size model of flexible membrane aeroshell using a Balloon from at a altitude of 39km

SeparationAscending

Launching

Mach number : 0.9 Dynamic pressure : 0.84kPa

Free Flight



Objectives

Development of a actual scale capsule-type vehicle with a deployable membrane aeroshell

Demonstration of the capability of the deployable membrane structure and the stable flight

Obtaining the aerodynamic characteristics and the behavior of the aeroshell in transonic and subsonic flow regimes



Flight Model

Capsule

Membrane Aeroshell

Outer Frame

• Hemispheric configuration• Material : Iron• Weight : 102 kg• Diameter : 60cm• All device were installed

• Flare configuration• Material : ZYLON• Weight : 0.6 kg• Maximum Diameter 150cm• Grid pattern was printed

• Dodecagonal configuration• Material : 12 Aluminum hollow pipes• Weight : 2.6 kg• Carpenter tape hinge deployment mechanism



Sensors• CCD camera • Fish eye lens• Acceleration Sensors • Angular Velocity Sensors• Geomagnetism Sensors• Pressure Transducer• Piezo Film• Thermo couple• GPS

Attitude and motionTrajectoryBehavior of AeroshellEnvironmental of Flight

All data were transferred to ground station by telemetry system



Deployment Demonstration

At Ground TestDeployed Configuration

Folded Configuration



Balloon flight

1. Mount the flight model2. Turn on all the sensors 3. Launching balloon4. Separation of the flight from

an altitude of 40 km5. Data transfer to the ground

during flight6. Splash down （ No

recovery ）7. Balloon and gondola is

recoveries.



Results

CCD image

Oscillation of the membrane aeroshell Deformation of the membrane aeroshell Attitude and rotation of the capsule

Horizontal Trajectory

Vertical Trajectory

Deceleration performance



CCD IMAGE

Two CCD cameras are equipped

外枠

魚眼レンズカプセル

膜面

ゴンドラ

紐

気球本体

カッター

Camera ２

Camera １



Membrane Oscillations

Output of piezo filmFFT analysis

Time variation of frequency spectrum

4Hz

10Hz

Membrane Aeroshell oscillated at a frequency of 4Hz and 10Hz



Membrane Deformation determiened from CCD Image through fish-eye lens

and assumption that membrane does not stretch

In Flight

Unloaded

Membrane aeroshell deformed to concave shape due to aerodynamic force



Attitude and RotationTrack of Sun in the CCD View

→Capsule did not inclined

Angular Velocity around body axis

→ Capsule rotated around body axis

Vehicle kept a vertical attitude with rotation during flight.



Horizontal Trajectory Horizontal Trajectory Wind and Horizontal Motion

→Capsule traveled in 6km horizontally →Horizontal Motion is synchronized with the wind

Vehicle dropped with zero angle of attack.



Vertical Trajectory History of Vertical Acceleration History of Vertical Velocity and Altitude

~ Comparison with simulation

→Flight data is in good agreement with trajectory Simulation



Aerodynamic Characteristics Mach Number vs Drag Coefficient

Drag Coefficient

Sq

mgGC zD

S=1.617m2

m=106kgg=9.8m/s2

Comparison with Wind Tunnel testPlot the flight data from 5km to 35 km→Flight data is good agreement

with Wind tunnel data

The flare-type membrane aeroshell has a reasonable deceleration performance in free flight condition as we expected at wind tunnel test.



Conclusions

The flight test of the capsule with flare-type membrane aeroshell was carried out using a Large scientific Balloon.

In flight test,

The flight model kept stable and vertical attitude The flight model dropped with a zero angle of attackThe 4Hz and 10Hz oscillations were induced

in both transonic and subsonic regime

The flight path and drag coefficient is in good agreement with the Trajectory analysis and wind tunnel test.

It is demonstrated the flare-type membrane aeroshell has a good deceleration performance



Wind Tunnel Test Low speed Wind Tunnel Test

Transonic Wind Tunnel Test

Concave shape

Tack-like Wrinkle

Drag Coefficient vs Angle of Attack



Separation Demonstration

Main rope

Cutter

Set up

Separation



Advantages

Dramatic Reduction of the Surface temperature

Reference Case （ Small sounding rocket ）

Mass = 50kgAltitude = 200kmDiameter = 20cmVelocity =1000m/s

flight experiment of the capsule with the deployable flexible aeroshell

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