Evolvable Mars Campaign Long Duration Habitation Strategies: Architectural Approaches to Enable Human Exploration Missions

Abstract

The Evolvable Mars Campaign (EMC) is the current NASA Mars mission planning effort which seeks to establish sustainable, realistic strategies to enable crewed Mars missions in the mid-2030s timeframe. The primary outcome of the Evolvable Mars Campaign is not to produce "The Plan" for sending humans to Mars, but instead its intent is to inform the Human Exploration and Operations Mission Directorate near-term key decisions and investment priorities to prepare for those types of missions. The FY'15 EMC effort focused upon analysis of integrated mission architectures to identify technically appealing transportation strategies, logistics build-up strategies, and vehicle designs for reaching and exploring Mars moons and Mars surface. As part of the development of this campaign, long duration habitats are required which are capable of supporting crew with limited resupply and crew abort during the Mars transit, Mars moons, and Mars surface segments of EMC missions. In particular, the EMC design team sought to design a single, affordable habitation system whose manufactured units could be outfitted uniquely for each of these missions and reused for multiple crewed missions. This habitat system must provide all of the functionality to safely support 4 crew for long durations while meeting mass and volume constraints for each of the mission segments set by the chosen transportation architecture and propulsion technologies. This paper describes several proposed long-duration habitation strategies to enable the Evolvable Mars Campaign through improvements in mass, cost, and reusability, and presents results of analysis to compare the options and identify promising solutions. The concepts investigated include several monolithic concepts: monolithic clean sheet designs, and concepts which leverage the co-manifested payload capability of NASA's Space Launch System (SLS) to deliver habitable elements within the Universal Payload Adaptor between the SLS upper stage and the Orion/Service module on the top of the vehicle. Multiple modular habitat options for Mars surface and in-space missions are also considered with various functionality and volume splits between modules to find the best balance of reducing the single largest mass which must be delivered to a destination and reducing the number of separate elements which must be launched. Analysis results presented for each of these concepts in this paper include mass/volume/power sizing using parametric sizing tools, identification of unique operational constraints, and limited comments on the additional impacts of reusability/dormancy on system design. Finally, recommendations will be made for promising solutions which will be carried forward for consideration in the Evolvable Mars Campaign work.

A Hybrid Power System for a Permanent Colony on Mars

“…India and Japan have expressed that their targets do not include Martian exploration whatsoever, while China do it independently, targeting manned missions to the Moon in 2030 in collaboration with Russia as a prior step [30,31]. Then, the Evolvable Mars Campaign is the current NASA mission seeking to enable crewed Mars missions in the mid-2030s timeframe [32]. Lastly, SpaceX is targeting the first manned mission to Mars in 2024 as preparation for a permanent settlement to be started shortly afterwards [5].…”

Limitations of Reliability for Long-Endurance Human Spaceflight

“…In addition, these missions will have endurances significantly longer than previous experience. For example, the Evolvable Mars Campaign (EMC) DSH must be designed to support the crew for 1,100 days in deep space on a Mars transit mission (round trip, including time in Mars orbit as a safe haven); 15 this is an endurance approximately 12 times longer than the typical resupply interval for the ISS. New approaches must be developed and implemented to mitigate risk and enable Earth-independent human spaceflight.…”

“…This section examines the impact of variation in reliability on the maintenance logistics mass required for a DSH on a 1,100 day Mars transit mission. 15 Component MTBFs are varied to represent both an increase and a decrease in reliability for some or all of the DSH critical system repairable items. Variation in reliability is implemented by multiplying the nominal MTBFs by an MTBF multiplier, η).…”

Human exploration missions to phobos prior to crewed mars surface missions

“…This section describes the mass estimates (Table 5) and delivery capabilities ( Figure 17) to support such a mission. The mass estimates for the habitat, Phobos taxi, and logistics were based on parametric models that have been developed and utilized for this and other architectural studies [7,35]. The mass of the PEV was based on a detailed mass equipment list derived from a combination of subsystem schematics and functional prototypes of various PEV subsystems, including the cabin structure, avionics, hatches, life support systems (including waste control and food systems), fusible heat sink, pressure control system, suit ports, and displays and controls..…”