Rashied Amini

Sample return missions are among the most difficult tasks for robotic spacecraft in exploring our solar system. However, the samples they return to Earth have significantly high value for the planetary science community. Thus far, we have only acquired samples from the Moon, three asteroids, a comet’s tail, and the solar wind at the Earth–Sun Lagrange Points. The National Academy’s most recent decadal survey of planetary science at NASA emphasized the value of samples returned to Earth for analysis and called for NASA to prioritize samples returned from Mars, the Moon’s South Pole, a Jupiter-family comet, and Ceres. Currently available rockets and propulsion technology impose severe, and possibly insurmountable, limits to where we can send robot explorers and return samples within a reasonable timescale. Now, the advent of large new rockets offers the potential for very high C₃ (characteristic energy) Earth escape trajectories. Parallel developments in Nuclear Propulsion yield much higher I_SP than chemical propulsion and can operate far away from the Sun. Our novel trajectory modeling results and mission architecture analysis show that, by combining these technologies, sample return from across the solar system becomes feasible within the career lifetime of a planetary scientist.

Sample return missions are the most difficult tasks we ask robotic spacecraft to undertake in exploring our solar system, but we do so because of the high value returned samples have for the planetary science community. Thus far, we have only acquired samples from: the Moon, three asteroids, a comet’s tail, and the solar wind at the Earth-Sun Lagrange Points. The National Academy’s most recent decadal survey of planetary science in NASA — Origins, Worlds, Life (OWL) — emphasized the value of samples returned to Earth for analysis and called for NASA to prioritize samples returned from Mars, the Moon’ South Pole, a Jupiter-family comet, and Ceres. Currently available rockets and propulsion technology impose severe, and possibly insurmountable, limits to where we can send robot explorers and return samples within a reasonable timescale. Now, the advent of large new rockets offers the potential for very high C3 Earth escape trajectories. Parallel developments in Nuclear Propulsion yield much higher ISP than chemical propulsion and can operate far away from the Sun. Our novel trajectory and mission architecture analysis shows that, combining these technologies, sample return from all across the solar system starts to become feasible within the career lifetime of a planetary scientist.