Human Mission to Phobos as an Introductory Mission to Mars

This investigation presents an evaluation of a nuclear thermal propulsion (NTP) transfer system for a 2035 crewed mission to Phobos. Phobos, the innermost of Mars' moons, is closer to its host planet than any other moon in the solar system and thus would serve as an excellent observation and teleoperation base for extensive exploration of the surface of Mars. It has an orbital period of 7 hours and 39 minutes allowing a, within the view, dwell time above key Mars locations of several hours. Establishing an outpost on Phobos before human surface missions provides a wealth of advantages. At Phobos the crew would explore its surface, gather samples, and teleoperate, in real time, Mars surface assets including rovers, helicopters, and balloons, in addition to establishing a communication relay system far superior to the current low altitude relay orbiters. In this paper, trajectory, vehicle and launch manifest information relevant to a piloted Phobos mission are discussed. This mission will serve as a technology pathfinder for later, more ambitious surface missions, validating all long duration habitation and Earth-Mars propulsion elements. This human journey to Phobos would be significantly less expensive and require a much shorter development schedule than that required of a Crewed Mars surface mission, in part because the large 17-meter diameter aeroshell, and the two 40-mt Mars landers (crew and cargo) would not be required.