Feasibility Assessment of Rapid Earth-Mars Transfers Using High-Power Electric Propulsion

The aim of this paper is to investigate the feasibility of an Earth-to-Mars transfer with reduced transfer time using a high-power electric propulsion system. The study involved a multidisciplinary analysis combining general performance calculations for power-limited systems, an analysis of a nuclear power source that might be available in the future, and a series of mission analyses, including trajectory optimization. The study quantified the importance of the specific mass of the power and propulsion system with regard to the objective of a fast transfer. A very fast Earth-to-Mars transfer in less than six weeks appears to be unrealistic in the medium term because it depends on a hypothetical breakthrough with the nuclear electric power source, requiring a specific mass that would typically be less than 1 kg/kW. The results obtained define the limits to improvements that could be obtained in the medium term, using power-generation technologies that, while challenging, are frequently considered as reasonably optimistic, for example using a high-temperature Brayton or Rankine conversion cycle. The shortest Earth-to-Mars transfer time that could be expected for missions with a large enough payload mass was found to be about 120 days, compared to 180 days with chemical propulsion.