Reentry Demonstration Plan of Flare-type Membrane Aeroshell for Atmospheric Entry Vehicle using a Sounding Rocket

Transcription

1 AIAA ADS Conference 2011 in Dublin 1 Reentry Demonstration Plan of Flare-type Membrane Aeroshell for Atmospheric Entry Vehicle using 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 MAAC / Membrane Aeroshell for Atmospheric-entry Capsule

2 2 Contents Background Low ballistic coefficient atmospheric entry system Our past research Reentry demonstration plan using sounding rocket Overview Experimental vehicle. Flight sequence Measurement items Development status of aeroshell Summary

3 3 Background HAYABUSA reentry Recently, 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 To support these space activities, the frequent, reliable and low-cost space transportation system between 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.

4 4 Low ballistic coefficient atmospheric-entry system One of the candidate to innovate the atmospheric entry is Low-ballistic-coefficient atmospheric-entry system using flexible aeroshell Various concept has been proposed and developed since 1960 Towed torus, balloon, Attached ballute, Conical ballute.. What is advantage of this concept?

5 5 Aeroshell effect on the aerodynamic heating Aerodynamic heating reduction effects is clarified by simple trajectory simulation for a virtual assumed reentry mission. Assumed re-entry mission Equilibrium T vs Aeroshell diameter 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 Heat flux estimation: Tauber s and Lees eq. 5m-diameter aeroshell stagnation Aeroshell Without aeroshell

6 6 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

7 7 Past Research Fundamental research and development starts ex. Supersonic wind tunnel and numerical simulation 2004 Flight test using a balloon Flight demonstration of vehicle with flare type membrane aeroshell Hypersonic wind tunnel test starts 2009 Deployment and flight test using balloon Deployment and flight demonstration of inflatable aeroshell 2011, next milestone is Reentry demonstration using a sounding rocket

8 8 Next milestone of development The experiment is carried out using a S-310 sounding rocket of ISAS/JAXA. S-310 Rocket specification Length : 7.1m Diameter : 0.31m Payload : 50kg Maximum Altitude : 150km In this test, the experimental vehicle which has 20kg total mass including flexible aeroshell, reenter atmosphere from 150km in altitude. <Main Objectives> S310-rocket of ISAS 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.

9 9 Experimental Vehicle 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. Space to pack the aeroshell Aeroshell cover 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 flare Made of ZYLON textile. Flare angle : 70 deg, outer diameter 100cm, Mass : 0.5kg

10 10 Test sequence 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. 5. Experimental vehicle reenter to atmosphere with large angle of attack. 1Hz 6. Aeroshell shape and vehicle attitude become stable by aerodynamic force. Reentry direction 7. At altitude about 55km Maximum Mach number: 4.45 Maximum heat flux: 18.6kW/m 2 Maximum dynamic pressure: 0.66kPa 1. Aeroshell is packed around the capsule when launching Separation mechanisms 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.

11 11 Flight trajectory Vehicle mass : 20kg, Aeroshell diameter : 1.2m, Drag coefficient : Initial 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 km The 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.

12 12 Measurement items and onboard sensors Aeroshell image 4 CCD cameras Flight trajectory GPS data. Pressure altimeter. Rader tracking. Attitude and motion 3D motion sensors (Accelerometer, angle velocity sensors, magnetic field sensor) 5 Pressure sensors on the capsule to measure the pressure distribution. Aerodynamic heating condition Thermocouples to measure temperature on the aeroshell Inflatable pressure Tiny pressure sensors embedded on the torus. Aeroshell image. All flight data are transmitted to the ground station with telemetry system during flight, because the experimental vehicle is not recovered in this test.

13 13 Device arrangement All electric device and gas injection system is arranged in the capsule. Capsule and onboard device is being developed now

14 14 Development status of Aeroshell Determination of flare angle. Durability against aerodynamic heating.

15 15 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 Local peak heating Shockwaves interacts on the aeroshell. Flow field oscillates Flare angle = 60deg There is only bow shock Flowfield is quite stable. The results suggests that the flare angle have to be more than 60 degrees.

16 16 Durability against aerodynamic heating The 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.

17 17 Summary The reentry demonstration using a S310 sounding rocket is planed and prepared. It is a important milestone of the development of the flare-type membrane aeroshell sustained by the inflatable torus for atmospheric entry vehicles. The flight test is planned to carry out in December 2011 at earliest. So, the experimental vehicle is being developed with hard work, now

18 18 Fin