Mars Ascent Vehicle Sizing and Habitability Assessment

The Mars Ascent Vehicle (MAV) is the single largest indivisible payload in the Evolvable Mars Campaign (EMC). The MAV cabin size drives ascent propellant load, which in turn drives In-Situ Resource Utilization and surface power needs, Lander payload sizing, and in-space transportation architecture--all of which determines how many Earth launches will be needed. The MAV cabin must accommodate crew suit don/doff, seat ingress/egress, exercise, and cabin ingress/egress, but there is currently no relevant test data on how much volume these activities will require.

This JSC collaborative project will produce detailed MELs for two MAV general arrangements as well as well as timelines for all mission phases. Specifically human factors studies would be performed with four subjects addressing different suit combinations, suit don/doffing, and window/workstations layouts, seat arrangements, sleeping accommodations, logistics stowage and utilization in two different configurations that would include a minimalist 2B lander cabin, and equivalent studies in a modified 2A cabin.

Note however, this reduced scope study will not include integration of the existing AES hardware (potable water, WCS, trash management systems), or the simulation software including rendezvous, subsystems models, and time delay simulator into a multi-day habitability study. Completion of the above work would be contingent upon additional funding from other sources.

The Mars Ascent Vehicle (MAV) is the largest indivisible payload and has the largest “gear ratio” in the EMC architecture, requiring between 7-15 kg of propellant to lift every kilogram of Mass of the Mars surface.  For these reasons the mass and volume of the MAV cabin drives requirements for the In-Situ Resource Utilization to generate propellants, which drives the surface power needs, and which also sets the Lander payload size, which drives the in-space transportation architecture, and the number of launches and time required to land humans on Mars Surface. Some of the architectures currently under consideration in the EMC utilize a chemical/solar Electric propulsion Hybrid that inserts into a 5 sol orbit and might require that the crew spend several days in the MAV prior to rendezvous with the Mars transit vehicle. There are a wide range of opinions regarding the required size of the MAV, but no Human in the loop evaluations to generate the data necessary to inform decisions on the MAV sizing, which are critical to begin to close the various EMC architectures.