The solar power sail is an original Japanese concept in which electrical power is generated by thin-film solar cells on the sail membrane. It can generate sufficient electric power to drive the high-specific ion engines in the outer planetary region. We propose a landing or sample return mission to explore a Jupiter Trojan asteroid directly using solar power sail. After rendezvousing with a Trojan asteroid, a lander separates from the solar power sail-craft to collect surface and underground samples, and perform an in-situ analysis in Plan-A/B. In addition, the lander delivers samples to the solar power sail-craft to return the sample in Plan-B. This paper shows a system design for the solar power sail-craft and introduces the latest mission analysis.
