Tradespace exploration of large Lunar Mars analog campaigns

A human mission to Mars will pose significant risks to crews due to limited abort options, lack of access to real- time support from mission control because of communication delays, along with radiation, medical emergencies, equipment failures, and behavioral changes. Our understanding of what is needed to effectively manage and mitigate these risks in terms of new technologies and mission architecture design is incomplete. To improve risk posture in complex human space architectures, one promising approach is to invest in operational experience, as illustrated by flight tests for new vehicles, and the Apollo, Shuttle, and ISS campaigns. In alignment with NASA’s Moon to Mars strategy, we investigated a lunar campaign architecture for the dual purposes of performing relevant analogs of future Mars missions and valuable lunar activities. This dual-use strategy aims to close knowledge gaps, retire risks and make the first Mars missions safer for crews, while also delivering value for lunar stakeholders. In this work, we performed a trade study of 23 alternative lunar Mars analog campaign architectures, each with 1 to 17 missions, using Standard Taguchi Orthogonal Arrays to efficiently explore campaigns with different number of missions, crew sizes, surface time, transit time, and safety margins. A key methodological contribution of this work is the development of a novel metric, the Elimination of Knowl- edge Gaps Indicator, EKG-i, which tracks the closure of 29 knowledge gaps and includes uncertainty reduction in mean- time-before-failure of 10 critical life-support systems and in 19 knowledge gaps related to the “red risks” tracked by the Human Research Program (HRP). The EKG-i metric normalizes the expected value of the number of “learning opportunities” for each modeled campaign vs. a threshold deemed sufficient for statistical inference purposes, thereby quantifying the relative capability of lunar Mars analog architectures to deliver Mars risk reduction. For alignment with both lunar and Mars ob- jectives, four benefit metrics were traded against the estimated lifecycle cost of each campaign architecture: (1) EKG-i, (2) the degree of international participation, (3) crew time available for science, and (4) the total investment in lunar infrastructure, as a proxy for commercialization potential. A composite benefit met- ric was constructed from some of the individual metrics using the analytic hierarchy process (AHP) to identify architectures with attractive combination of benefits. The selected 13-mission, 154-crew, 6-year MARTEMIS campaign architecture, which received a Best in Theme Award at the 2024 NASA RASC-AL competition, includes a concept of operations and descriptions of a dual-habitat architecture, mission control framework, and technology roadmaps. MARTEMIS delivers a predicted 77% EKG-i (Mars knowledge gap closure), international participa- tion of 22 Artemis Accords (AA) members, 296 crew-months of lunar science and exploration, and the deployment of 56 habitable modules/rovers for a life cycle cost of $94.8B and a $1.75B per annum (p.a.) cost to NASA. Overall, MARTEMIS simultaneously delivers on informing and accelerating the de- velopment of a safe and cost-effective initial Mars exploration mission and on the vision of a lunar permanence campaign, thereby promoting sustainable human space exploration.