Sample and return mission from asteroid Nereus via solar electric propulsion

Abstract

The sample and return mission to near Earth asteroid Nereus (4660) via an electric propulsion is presented in this paper, which is investigated at the Institute of Space and Astronautical Science (ISAS). An ion thruster is assumed here for Solar Electric Propulsion (SEP), which enables even the smallest spacecraft that weighs about only 350 kg to accomplish that difficult mission. ISAS is scheduling to launch one Lunar and one Martian orbiter in 1997 and 1998 via its own transporter M-V. And this concept follows them next in the launch window of 2002. The approach and exploration scenario to Nereus are also described here in detail, among which the mapping as well as sampling sequences are focused on. Especially, the sampling scheme proposed here is the characteristic point featuring an ‘artificial landmark’, which is the target plate dropped on the surface. This is used for the spacecraft to make a rendezvous autonomously with it via an optical aid onboard. Samples are assumed to be recovered via a hyperbolic reentry capsule on the ground. Practical weight estimation based on some heritages of ISAS does firm the spacecraft design feasibility.