1. How Do You Qualify Heat Shields on Earth? April 14, 1982 Space Shuttle Columbia STS-003 Kuiper Airborne Observatory Infra-Red image

2. Or: Electric Arc Jet Testing at NASA Ames 1998 Ames IHF arc jet facility Ablating disk with bow shock INITIALS-2

3. CSC/SETI Institute Colloquium Series July 29, 2009 John Balboni Thermo-Physics Facilities NASA Ames Research Center December 2004 Meridiani Planum Mars Exploration Rover Opportunity Heat shield and impact site INITIALS-3

4. Heat Shield: ~10% of landed mass 820 kg (rover, lander, heatshield, parachute) ~$820,000,000 for two Mars Rovers (APPROXIMATE) ~$500,000 per kg landed mass (two rovers)(APPROXIMATE) two Heat Shields cost ~$80,000,000 (APPROXIMATE) Heat Shields: Impact on Science INITIALS-4

5. INITIALS-5 Galileo entry probe was 45% heat shield: 150 kg “dead” wt. Mass Science payload mass is inversely proportional to the “delivery” mass, including the heat shield Galileo Jupiter Probe: 1995

6. INITIALS-6 Columbia STS-107: April 1, 2003 Heat shield failure may lead to complete failure of the mission and loss of the spacecraft

7. R&D: provide critical data for the research and development of thermal protection (TPS) materials Flight Qualification/Sustaining Engineering: qualify/certify TPS materials and processes for National Programs Instrumentation: Develop surface and in-depth instruments and sensors Space Ops: Support TPS damage assessment and verification of repair techniques for crewed spacecraft Rationale for Arc Jet Testing X-33 SHARP B1 & B2 NASP PAET V IKING P IONEER- V ENUS G ALILEO MER M AGELLAN P HOENIX S TARDUST M ARS P ATHFINDER Orion S PACE S HUTTLE A POLLO X-37 FALCON/CAV INITIALS-7 Space Shuttle Tile Damage

8. INITIALS-8 Acknowledgements Contributions and charts provided by: Dr. Michael Wright, NASA Ames Dr. George Raiche, NASA Ames Dr. Bernie Laub, NASA Ames Ernest Fretter, NASA Ames Bonnie James, NASA Marshall Space Flight Center

9. INITIALS-9 Summary: The Problem (and Solution) The Analyses The Experiments The Facilities

10. INITIALS-10 The Problem (and Solution)

11. INITIALS-11 The Solution: Blunt Bodies_2

12. INITIALS-12 Stardust Mission: Video (play video here)

13. INITIALS-13 The Root Problem: Speed Physics dictates high speeds for space travel. Consider circular orbits at 1.025 x Radius: Satellite SpeedEscape Speed Mars........ 3.5 km/sec 5.0 km/sec Venus....... 7.2 km/sec10.3 km/sec Earth........ 7.8 km/sec11.2 km/sec Jupiter...... 41.7 km/sec59.5 km/sec Kinetic Energy ~ mV 2 Surface Convective Heat Transfer Rate ~ V 3

14. INITIALS-14 The Solution: Blunt Bodies

15. INITIALS-15 The Solution: Blunt Bodies

16. INITIALS-16 The Solution: Blunt Bodies

17. INITIALS-17 The Solution: Blunt Bodies MSL = Mars Science Laboratory (rover); 2011 Launch

18. INITIALS-18 The Space Shuttle: Thermal Protection RCG Coating FRCI-12 Tile Gap Fillers AIM-22 Tile AFRSI Blanket TUFI/AETB Tile

19. INITIALS-19 The Analyses

20. INITIALS-20 Hypersonic Flight: Analysis

21. INITIALS-21 Hypersonic Flight: Analysis CFD = Computational Fluid Dynamics

22. INITIALS-22 Hypersonic Flight: Analysis

23. INITIALS-23 Hypersonic Flight: Analysis Except for Space Shuttle, all past Earth entry vehicles and all planetary entry vehicles use “Ablative” heat shield materials. TPS = Thermal Protection Sysetm (Heat Shield)

24. INITIALS-24 Ablative Heat Shield: Physics

25. INITIALS-25 Ablative Heat Shield: Physics

26. INITIALS-26 The Experiments

27. INITIALS-27 Arc Jet Test Objective Verify on the ground the heat shield integrity before atmospheric entry Develop and characterize material properties Screen candidate materials Verify heat shield design: gaps, attachments Develop and characterize instrumentation Verify heat shield repair techniques Example:

28. INITIALS-28 Arcjet Diagnostics and Analysis: Flight Traceability example Entry vehicle shape is established, Aerothermal analysis predicts the flight environment Arc Jet flow analysis determines appropriate arc jet test configuration and in-depth material response Arc jet diagnostics measure the free-stream conditions and material response Calibration Data and Pre-Test Predictions Comparing experimental and modeling data confirms arcjet-to- flight correspondence TPS is sized to the aerothermal environment; Final arc jet tests establish TPS flight certification and 3 TIRS rockets with covers were added at a late date MER TIRS flight article CFD solution of TIRS cover and backshell TPS arc jet test in PTF Photo of TIRS arc jet test in PTF MER aeroshell in 3D with chemically reactions in the flow and at the surface

29. INITIALS-29 Space Shuttle Wing Leading Edge Repair Pre-test: 9x9 inch panel with 7’’ plug repair 15 min. arc-jet test; exceeding 2000 C on the material

30. INITIALS-30 The Facilities

31. INITIALS-31 Arc Jet Complex STATUS: Operational (Commissioned 1962) LOCATIONS: N-234 and N238 Four Arc-Jet Facilities: Aerodynamic Heating Facility (20 MW) 2-By- 9-Inch Supersonic Turbulent Flow Duct (20 MW) Panel Test Facility (20 MW) Interaction Heating Facility (60 MW) One of only three such facilities in the US; (Two NASA, One DoD)

32. INITIALS-32 IR image of tile panel; Top view Flow Panel test in semi-elliptical flow nozzle; side view; 80 cm x 80 cm Arc Jet Panel Test

33. Arc Jet Schematic Objective: Simulate entry heating in a ground-test facility Goal: Verify a thermal protection material/system design before flight; support continuing engineering during operations Method: Heat a test gas (air) to plasma temperatures by an electric arc, then accelerate into a vacuum chamber and onto a stationary test article Vacuum Test Chamber High Energy Flow Mach 5 - 7 at exit 10-45 MJ/kg Simulates altitudes 30–60 kmGas Temp. > 8,000 K ARC HEATERNOZZLETEST CHAMBER

34. Ames High Enthalpy Test Facilities Panel Test Facility 20 MW - TPS Panel Testing Aerodynamic Heating Facility 20 MW - TPS Free Jet Testing Interaction Heating Facility 60 MW - TPS Free Jet and Panel Testing 2”x9” Turbulent Flow Duct 20 MW - TPS Panel Testing INITIALS-34

35. Arc Jet Test Crew

36. Arc Jet Photo Arc Jet Test Samples

37. Arc Jet Walk-Around (play video here)

38. Arc Jet Test (play video here)

39. INITIALS-39 Future Human Exploration

40. INITIALS-40 Scenario: Lunar Exploration EXAMPLE ONLY All lunar sorties require Earth return entry vehicle: Reference ESAS Requirements Study, June 1, 2005

41. INITIALS-41 Candidate CEV Configuration Reference ESAS Requirements Study, June 1, 2005 Ames is positioning itself for a major role in TPS design

42. INITIALS-42 Summary - Conclusion