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Review of Past and Proposed Mars EDL Systems. Past and Proposed Mars EDL Systems. MinMars Mars entry body design is derived from JPL Austere Mars entry body design (blue fields fixed) MinMars entry velocity may be higher due to direct entry May need to perform aerocapture prior to Mars entry?.
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Past and Proposed Mars EDL Systems • MinMars Mars entry body design is derived from JPL Austere Mars entry body design (blue fields fixed) • MinMars entry velocity may be higher due to direct entry • May need to perform aerocapture prior to Mars entry?
JPL Austere Mars Entry Body 30 degrees side-wall angle
MSL is designed to support landing altitudes as high as 2 km MOLA • Primary drives is science access • Driving considerations for MinMars: • Solar power system performance, drives towards 30 deg N • Soil / ground water content • Facilitation of Mars EDL • It seems that the MinMars considerations can be supported by landing sites with -2 km MOLA or less
MSL Technology Extension for Ballistic Coefficient 115 kg/m2 MSL reference 2000 kg payload Delivery of ~2000 kg of usablepayload achievable with MSLtechn. (see NASA Mars DRA 5.0)
2 mt lander based on MSL technology 7.3 m 4.6 m
Transportation assessment assuming capability for 1 mt usable surface payload • Crew transportation: • 2 crew per 25 mt package • In-space habitat that is discarded prior to aerocapture / entry • 2 crew either enter together in single aeroshell or each crew has individual aeroshell • Transportation of supplies and spare parts • Can be scaled down and delivered with individual aeroshells in 1 mt packages • Transportation of power and ISRU systems • Can be scaled down and delivered with individual aeroshells in 1 mt packages • Transportation of unpressurized mobility systems • Can be scaled down and delivered with individual aeroshells in 1 mt packages • Transportation of habitat and workshop • Difficult, may require inflatable modules with interior outfitting; subsequent assembly on the surface ?
Basis: JPL Austere Mars Entry Body 30 degrees side-wall angle
Mars Science Laboratory (MSL)and MinMars Entry, Descent &Landing (EDL) comparison Vehicles and crew member notionally to scale MSL data from: Mars Exploration Entry, Descent andLanding Challenges, Braun RD, Manning RM, 2006
Major EDL Challenges for MinMars • Significantly higher ballistic coefficient than MSL • Lower landing altitude than for MSL helps (denser atmosphere) • Landing altitude possibly as low as -2 km • Higher landing accuracy • 2-5 km vs. 20 km • But pre-deployed assets available (in orbit and on the ground) • No use of main parachute(s) • Vehicle never slows down sufficiently for existing parachute technology (< Mach 2); also issues with chute scaling • All-propulsive descent will likely be required • Possibly use of a supersonic drogue parachute for aeroshell forebody separation and stabilization • Off-center aerodynamic heating • Large aeroshell diameter leads to different Re-number regime, turbulent flow over forebody heat shield • Maximum heating may no longer occur at center / nose of heat shield but off-center in turbulent region Question: in a worst-case scenario, could we deliver MinMars infrastructureand crew with existing (Viking-based) EDL technology (or extensions thereof)?