Combining Solar Electric Propulsion and chemical propulsion for crewed missions to Mars

Abstract

This paper documents the results of an investigation of human Mars mission architectures that leverage near-term technology investments and infrastructures resulting from the planned Asteroid Redirect Robotic Mission (ARRM), including high-power Solar Electric Propulsion (SEP) and a human presence in Lunar Distant Retrograde Orbit (LDRO). The architectures investigated use a combination of SEP and chemical propulsion elements. Through this combination of propulsion technologies, these architectures take advantage of the high efficiency SEP propulsion system to deliver cargo, while maintaining the faster trip times afforded by chemical propulsion for crew transport. Evolved configurations of the Asteroid Redirect Vehicle (ARV) are considered for cargo delivery. Sensitivities to SEP system design parameters, including power level and propellant quantity, are presented. For the crew delivery, liquid oxygen and methane stages were designed using engines common to future human Mars landers. Impacts of various Earth departure orbits, Mars loiter orbits, and Earth return strategies are presented. The use of the Space Launch System for delivery of the various architecture elements was also investigated and launch vehicle manifesting, launch scheduling and mission timelines are also discussed. The study results show that viable Mars architecture can be constructed using LDRO and SEP in order to take advantage of investments made in the ARRM mission.

Human exploration of Phobos

“…Robotic precursor data will eventually be required to characterize the gravitational field, identify regions of scientific interest and hazards, characterize soil mechanics for analysis of hopper efficiency and dust environment, and to identify and characterize any useful materials that could be used for demonstration of in situ resource utilization. 9. A pair of core exploration module designs of different sizes may offer the opportunity of sensible commonality, reuse, and evolution of systems across multiple mission destinations within the Evolvable Mars Campaign.…”

“…Crew Size-It was assumed in all mission architectures that a four-person crew transits from Earth to a one-sol HMO [9,10]. However, it is assumed in Cases A and B that only two of the four crewmembers transit in a crew taxi from HMO to Phobos, with two crewmembers remaining in HMO.…”

“…All such habitats were assumed to be predeployed by a solar electric propulsion (SEP) tug spacecraft [9,10], which would also be used to provide solar power for the habitat. Options for orbital (Case D) as well as fixed (Cases E and F) and mobile (Case G) versions of a Phobos surface habitat were considered.…”

“…Power systems, illumination, and communications constraints -studied in detail by Pratt and Hopkins [6] -were not evaluated in this study and are being incorporated into follow-on analyses at the time of writing. In this study it was assumed that a fixed surface habitat (Cases E and F) would utilize the 150kW to 400 kW arrays of the SEP used for predeployment [9,10], combined with adequate energy storage to accommodate night (average 3.8 hours) and eclipse (maximum 54 minutes) periods.…”

Solar Electric Propulsion Concepts for Human Space Exploration

“…21 Use of this structure to accommodate the higher capability is described in Section IV.C. 23 As previously described, NASA's evolvable Mars campaign includes investigating a split architecture that employs SEP to preposition cargo to Mars and chemical propulsion to transport crew. The Block 1 SEP bus and thruster system concept shown in Fig.…”