Flight Performance of the Inflatable Reentry Vehicle Experiment 3 10 th International Planetary Probe Workshop June 21, 2013 Robert Dillman 1, John DiNonno.

Flight Performance of theInflatable Reentry Vehicle Experiment 3

10th International Planetary Probe WorkshopJune 21, 2013

Robert Dillman1, John DiNonno1, Richard Bodkin1, Valerie Gsell2, Nathanael Miller1, Aaron Olds3, and Walt Bruce1

1: NASA Langley Research Center, Hampton, VA2: NASA Wallops Flight Facility, Wallops Island, VA

3: Analytical Mechanics Associates, Hampton, VA

[email protected]

Separate RV & Nose ConeFrom Brant & Transition90s, 148km

Yo-Yo De-Spin, 80sBrant Burnout, 56.9sBrant Ignition, 23.0sTaurus Separation 21.0sTaurus Burnout, 18.5sTaurus Ignition, 15.0sTalos Burnout, 6.4sSpin Motor Ignition, 0.9sLeaves Rail, 0.5sTalos Ignition, 0s

Launch on Black Brant-XI from WFF940lb payload, El 84deg, Az 155deg

Atmospheric Interface, 25Pa (664s, 85km)

RV Peak Heat Rate 14.4W/cm2678s, 50km, Mach 7 (peak Mach 9.8)

RV splashdown at 30m/s1194s (447km downrange)

Eject Nose Cone102s, 176km

Apogee364s, 469km

RV Peak Dynamic Pressure 6.0KPa683s, 40km, 20.2g’s

Reentry Experiment Complete at Mach < 0.7 (707s, 28km)

Coast…

Actuate CG offset system628s, 127km (1s duration)

Start Aeroshell Inflation436s, 448km (86s to 52KPa [7.5psi]) (186s to 138KPa [20psi])

ACS Reorientation587s, 260km (40s duration)

NIACS damps rates91s (10s duration)

LOS by land radar & TM910s, 10.5km

Vent NIACS and Inflation System Gas

Bonus CG Offset Maneuvers

Recovery Attempt - Unsuccessful

IRVE-3 Mission Events

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Mission Objectives (Results)IRVE-3, 7/23/121) Demonstrate reentry survivability of an inflatable with flight relevant heating.

(Saw peak heat flux 14.4W/cm2, peak deceleration 20.2G’s.)2) Demonstrate the effectiveness of a movable CG on the flight L/D of an

inflatable. (Reentered with L/D=.17, lift up. Shifted to lift down after reentry; inflatable essentially acted as a rigid body.)

IRVE-II, 8/17/091) Flight demonstration of inflation and reentry survivability. (Inflation system

held pressure in RV. RV stable in hyper/super/trans/subsonic flight.)2) Assess thermal and drag performance of an inflatable RV. (Worked as planned.)3) Collect flight data for comparison with analysis & design. (Worked as planned.)

IRVE (a.k.a. IRVE-I), 9/6/07• Same objectives that were re-used on IRVE-II.• Launch vehicle failed to release payload. (IRVE-II build-to-print re-flight)• Demonstrated could pack and deploy inflatable structure, flexible TPS with

negligible damage to the materials.

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IRVE-3 Reentry Vehicle• 3m [118”] diam inflatable aeroshell with flexible TPS on forward surface• Centerbody houses inflation system, CG offset mechanism, telemetry

module, power system (batteries), ACS, cameras• Inflatable aeroshell packs to 18.5” diam inside nose cone for launch • Restraint cover holds aeroshell packed for launch; pyrotechnic release• Inflation system fills aeroshell from 3000psi Nitrogen tank• Attitude control system uses cold Argon thrusters to reorient for entry• CG Offset mechanism allows evaluation of inflatable aeroshell L/D• RV entry mass 281kg

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Stowed (18.5”)

22” diam

18.5” diam

Inflation SystemCG Offset System

TM & Power

ACS

Cameras

Deployed (3m [118”] diam)

Inflatable

Flexible TPST1

T2T3

T4T5

T6 T7

Structure

Nextel

Nextel

Kapton/Kevlar

Aeroheating andDynamic Pressure

TPS Layup

Pyrogel

Pyrogel

IRVE-II upgrades to IRVE-3

• Same: stacked torus structure, 3m diameter, 60° cone angle• Total redesign of inflatable structure (ILCHDT/Airborne); more robust (3.520 psi);

lower leak rate• Upgraded TPS:

– IRVE-II was demo of inflation & viability, negligible heating, no TPS insulation– IRVE-3 upgraded to a flight-relevant layup, Nextel over Pyrogel

• Replaced Teflon nose with TPS-covered aluminum one– Nose instrumentation was not folded during packing, more sensors viable– Sharpened nose radius, to raise stagnation heat flux on TPS

• Increased instrumentation: Added 5 heat flux gauges & pressure ports centered on stag pt; added IMU & GPS; more thermocouples; 4 cameras for 360° view

• Improved inflation system: Used metering valve that closed when inflatable was full, instead of dumping gas overboard through pressure relief valves

• Larger sounding rocket produced higher apogee (218469km)• More hardware in larger centerbody (10.7522in), with same diameter aeroshell, raised

ballistic coefficient 12.526.9kg/m2, raised heat flux 2.214.4W/cm2, G’s 8.520.26/21/2013 IPPW-10 5

Packing the IRVE-3 Aeroshell

• NC-machined cap attached to nosecone air spring– Helps support aeroshell

during launch, pushes nosecone clear in flight

• Volume allocated inside LV nosecone: 7966in3

• Final volume used (laser scan): 5994in3

• Final packed density 39lb/ft3

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• Aeroshell attached to inflation system skin, then packed

IRVE-3 Flight Video

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Surprise: Pothole in the Sky• At 46km, deceleration dropped from

16 to 14.5G’s for 100ms.• Registered at same time on multiple

sensors.• Best explanation: 11% local drop in

density. (Such drops are not in GRAM, but have been seen before in Shuttle reentry flights.)

• Structural engineer used data to verify modal vibration frequencies

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IRVE-3 TPS Temperatures

• Thermocouple stacks in TPS showed expected heating trends• Lower peak values than expected; maximum temperature reading was 387C• Heat flux measurements agreed with trajectory reconstruction• Large (0.063in) thermocouple size gave slow response; missed peak temps• Thermocouple beads were not in good thermal contact with low-density TPS6/21/2013 IPPW-10 9

IRVE-3 Centerbody Temperatures• Outer surfaces warmed to 150C during launch,

then cooled• Camera deck was covered during launch, then

heated to 50C from electrical power & weak entry heating

• Inflation system structure stayed at room temperature throughout flight (protected by TPS, and position down in entry cone)

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Reentry

IRVE-3 Recovery Attempt• RV splashdown 1.8s long, ~50 miles beyond nominal• Radar track provided latitude/longitude for recovery• Surveillance aircraft found object in water ~1 mile from predicted

location; had 1hr loiter fuel after splashdown• Recovery boat needed ~2hrs to reach splashdown location

• Debris from damaged fishing boat; not our hardware.6/21/2013 IPPW-10 11

Aircraft Surveillance View from Recovery Boat

The Future• IRVE-3 showed an inflatable aeroshell can handle a flight-relevant

reentry environment, and that an offset CG can be used to steer an inflatable.

• Future flights will hopefully demonstrate the increased capabilities that the HIAD project has developed in parallel with IRVE-3. TPS capabilities are now more than 3x higher than what IRVE-3 used.

• Several proposals exist for HIAD demonstrations from Earth orbit, which will hopefully pave the way to eventual flight use.

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Thanks

• Many thanks to the entire IRVE-3 team and all those who supported us for their long hours and dedication.

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For More Information1. IRVE-3 Post-Flight Analysis Review, NASA Langley Research Center, March

2013.2. Dillman R. A., Hughes S. J., Bodkin R. J., Bose D. M., Del Corso J., and

Cheatwood F. M., Flight Performance of the Inflatable Reentry Vehicle Experiment II, 7th International Planetary Probe Workshop, Barcelona, Spain, June 2010.

3. Dillman R. A., Gsell V. T., and Bowden E. L., Attitude Control Performance of IRVE-3 (AAS 13-077), 36th Annual AAS Guidance & Control Conference, Breckenridge, Colorado, February 2013.

4. Olds A. D., Beck R. E., Bose D. M., White J. P., Edquist K. T., Hollis B. R., Lindell M. C., Cheatwood F. M., Gsell V. T., and Bowden E. L., IRVE-3 Post-Flight Reconstruction (AIAA 2013-1390), 22nd AIAA Aerodynamic Decelerator Systems Technology Conference, Daytona Beach, Florida, March 2013.

5. Findlay J. T., Kelly G. M., and Troutman P. A., FINAL REPORT: Shuttle Derived Atmospheric Density Model (NASA CR-171824), December 1984.

6. Hughes S. J., Cheatwood F. M., Calomino A. M., Wright H. S., Wusk M. E., and Hughes M. F., Hypersonic Inflatable Aerodynamic Decelerator (HIAD) Technology Development Overview, 10th International Planetary Probe Workshop, San Jose, California, June 2013.

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