Sensitivity Analysis of CFM Technologies for Combined NEP-Chemical Mars Missions

Cryogenic fluid management (CFM) technologies will be crucial in enabling crewed missions to Mars with advanced propulsion systems. The Compass Team, which performs concurrent engineering at NASA Glenn Research Center, examined the sensitivity of a nuclear electric propulsion (NEP) combined with chemical propulsion (NEP-Chem) crewed Mars mission to the performance of various CFM subsystem elements. Specifically, the team examined the robustness of the mission to the valve leak rates, residuals, and the specific mass and power of the cryocoolers. A similar analysis was performed by the Advanced Concepts Office (ACO) at NASA Marshall Space Flight Center looking at the effects of the same technologies' performance on a nuclear thermal propulsion (NTP) crewed Mars mission. This paper will include a discussion of the results of the NEP-Chem analyses. Discussion of the NEP-Chem analysis will include the impacts of varying each of the CFM technologies' performance to both the vehicle design and the trajectory, noting where breakpoints occurred. The results of both the Compass and ACO analyses provide information on which CFM technologies must meet their performance goals to enable Mars missions. Additionally, the NEP-Chem results speak to the mission robustness afforded by having two separate propulsion systems.