International Planetary Probe Workshop 10 Entry, Descent, and Landing Systems Short Course Subject: Supersonic Retropropulsion Author: Karl Edquist NASA Langley Research Center sponsored by International Planetary Probe Workshop 10 June 15-16, 2013 San Jose, California

International Planetary Probe Workshop 10 Short Course 2013 Outline Introduction Recent Work Recommended Next Steps June 15-16, 2013 International Planetary Probe Workshop 10 Short Course 2013

International Planetary Probe Workshop 10 Short Course 2013 Introduction MSL EDL Mars EDL with SRP (NASA/TM-2010-216720) Problem: Mars EDL technologies are nearing their payload limit Mars Science Laboratory = 4.5 m aeroshell + 21.5 m parachute = 0.9 t payload Larger supersonic parachutes are inhibited by scaling challenges Goals beyond MSL: More mass (10s of t) Better accuracy (meters) Higher landing elevation Solution: Use propulsive deceleration = Supersonic Retropropulsion (SRP) SRP is considered to be enabling for human-scale (5-40 t) & enhancing for robotic-scale (2-5 t) Mars EDL 1.8 MN O/CH4 3-4 Earth g’s 0.9 t payload “As Mars missions approach human class entry masses, the required size of supersonic deployable aerodynamic decelerators renders them impractical…initiation of propulsive deceleration must occur earlier in the descent phase…SRP becomes an enabling technology for human class Mars missions.” - NASA EDL Roadmap (TA09), November 2010. 40 t payload June 15-16, 2013 International Planetary Probe Workshop 10 Short Course 2013

SRP Early Developments Wind tunnel tests from 1950s to 1970s studied SRP as an augmentation to aerodynamic deceleration General aerodynamic trends were observed, but no development beyond the laboratory CD,Total = CD,Aero + CT CT (= T/q∞Sref) known from engine thrust and trajectory conditions CD,Aero depends on vehicle geometry, jet configuration & thrust magnitude Jarvinen, NASA CR NAS 7-576, 1970 Long period of inactivity from 1970s to 2000s 1 Jet, High Thrust 3 Jets, Low Thrust Mach > 1 Jet June 15-16, 2013 International Planetary Probe Workshop 10 Short Course 2013

International Planetary Probe Workshop 10 Short Course 2013 SRP in EDL Project (2010-2011) Wind Tunnel Testing Mach 1.8 to 4.6 Cold gas jets CT = T/(q∞Sref) = 0 to ~10 Surface pressure & high-speed video LaRC 4x4 ARC 9x7 CFD Modeling CFD complicated by unsteady & turbulent flow Promising qualitative (flowfield structure) & quantitative (pressure) comparisons to wind tunnel data DPLR FUN3D OVERFLOW Mach 4.6, CT = 2 Flight Test Conceptual Design Sounding rocket platform Engine options, notional mass & packaging Open Issues Vehicle configurations, engine development, aerodynamic stability, aerothermodynamics, vehicle transitions, ground interactions, flight tests June 15-16, 2013 International Planetary Probe Workshop 10 Short Course 2013

NASA LaRC UPWT Test, Mach 4.6, AoA = 0 No Jets 1 Jet, CT = 2 3 Jets, CT = 2 4 Jets, CT = 2 June 15-16, 2013 International Planetary Probe Workshop 10 Short Course 2013

CFD of NASA LaRC UPWT Test 3 Jets, Mach 4.6, AoA = 12, CT = 3 DPLR OVERFLOW FUN3D June 15-16, 2013 International Planetary Probe Workshop 10 Short Course 2013

SRP Recommended Next Steps Define reference vehicles (robotic & human) Allows sizing of propulsion system (engines, tanks, etc.) Complete hot-fire engine tests Provides data for startup transients & effect on vehicle aerodynamics Develop large (100s of kN) throttle-able engines Required for engine use through touchdown Complete Earth-based & Mars precursor flight tests at progressively higher scale & complexity Reduces risks for mission infusion Eventually includes vehicle transitions & touchdown Develop high-fidelity EDL simulations SRP mass, packaging & performance CFD-based aerosciences tools June 15-16, 2013 International Planetary Probe Workshop 10 Short Course 2013

International Planetary Probe Workshop 10 Short Course 2013 References Adler, M., Wright, M., Campbell, C., Clark, I., Engelund, W., and Manning, R. M., “DRAFT Entry, Descent, and Landing Roadmap, Technology Area 09," National Aeronautics and Space Administration, http://www.nasa.gov/oces/oct/home/roadmaps/index.html, November 2010. Dwyer-Cianciolo, A., et al, “Entry, Descent and Landing Systems Analysis Study: Phase 1 Report,” NASA/TM-2010-216720, July 2010. Dwyer-Cianciolo, A., et al, “Entry, Descent and Landing Systems Analysis Study: Phase 2 Report on Exploration Feed Forward Systems,” NASA/TM-2011-217055, February 2011. Korzun, A., “Aerodynamic and Performance Characterization of Supersonic Retropropulsion for Application to Planetary Entry and Descent,” Ph. D. Dissertation, Department of Aerospace Engineering, Georgia Institute of Technology, Atlanta, GA, 2012. Edquist, K., et al, “Development of Supersonic Retro-Propulsion for Future Mars Entry, Descent, and Landing Systems,” AIAA Paper 2010-5046, AIAA Fluid Dynamics Conference, Chicago, IL, 28 June-2 July 2010. Berry, S., et al, “Supersonic Retro-Propulsion Experimental Design for Computational Fluid Dynamics Model Validation,” IEEEAC Paper 1499, IEEE Aerospace Conference, Big Sky, MT, 5-12 March 2011. Berry, S., Rhode, M., Edquist, K., and Player, C., “Supersonic Retropropulsion Experimental Results from the NASA Langley Unitary Plan Wind Tunnel,” AIAA Paper 2011-3489, AIAA Thermophysics Conference, Honolulu, HI, 27 - 30 June 2011. Berry, S., Rhode, M., and Edquist, K., “Supersonic Retropropulsion Experimental Results from the NASA Ames 9- x 7-Foot Supersonic Wind Tunnel,” AIAA Paper 2012-2704, AIAA Fluid Dynamics Conference, New Orleans, LA, 25-28 June 2012. Rhode, M., and Oberkampf, W., “Estimation of Uncertainties for a Supersonic Retro-Propulsion Model Validation Experiment in a Wind Tunnel,” AIAA Paper 2012-2707, AIAA Fluid Dynamics Conference, New Orleans, LA, 25-28 June 2012. Trumble, K., Schauerhamer, D., Kleb, B., and Edquist, K., “Analysis of Navier-Stokes Codes Applied to Supersonic Retro-Propulsion Wind Tunnel Test,” IEEEAC Paper 1471, IEEE Aerospace Conference, Big Sky, MT, 5-12 March 2011. Trumble, K. et al, “An Initial Assessment of Navier-Stokes Codes Applied to Supersonic Retro-Propulsion,” AIAA Paper 2010-5047, AIAA Fluid Dynamics Conference, Chicago, IL, 28 June-2 July 2010. Kleb, B., et al “Toward Supersonic Retropropulsion CFD Validation,” AIAA Paper 2010-5047, AIAA Thermophysics Conference, Honolulu, HI, 27 - 30 June 2011. Schauerhamer, D., et al, ”Continuing Validation of Computational Fluid Dynamics for Supersonic Retropropulsion,” AIAA Paper 2012-864, AIAA Aerospace Science Meeting & Exhibit, Orlando, FL, 9-13 January 2012. Zarchi, K., Schauerhamer, D., Kleb, B., Carlson, J. R., and Edquist, K., “Computational Fluid Dynamics Validation and Post-Test Analysis of Supersonic Retropropulsion in the Ames 9×7 Unitary Tunnel,” AIAA Paper 2012-2705, AIAA Fluid Dynamics Conference, New Orleans, LA, 25-28 June 2012. Post, E., Dupzyk, I., Korzun, A., Dyakonov, A., Tanimoto, R., and Edquist, K., “Supersonic Retropropulsion Flight Test Concepts,” 8th International Planetary Probe Workshop, Portsmouth, VA, 6-10 June 2011. June 15-16, 2013 International Planetary Probe Workshop 10 Short Course 2013