Trajectory options for a manned mission to mars using high-thrust propulsion systems

An analysis has been done of performance factors (mission duration, initial mass of the interplanetary crew transfer vehicle, velocity of the re-entry into the Earth atmosphere of the descent vehicle with the crew) for a single-spacecraft manned mission to Mars using high-thrust propulsion systems. Locally optimal solutions (in terms of delta-V budgets for the transfer) were found for the Earth-Mars-Earth transfer, with varying periods of waiting in Mars orbit, minimal distance to the Sun, as well as flight paths (direct Earth-Mars-Earth transfers vs. gravity assist maneuvers at Venus during Earth-Mars or Mars-Earth transfers). The proposed classification for locally optimal solutions is applicable to both high-thrust propulsion systems and low-thrust propulsion systems. A comparison of performance factors has been done for manned Martian mission options based on liquid-propellant engines and nuclear rocket engines with a 12,5 km/s constraint on the velocity of the manned re-entry vehicle in the Earth atmosphere.