Current Activities of JAXA's Interplanetary CubeSats and Micro-sats

The University of Tokyo and Japan Aerospace Exploration Agency (JAXA) developed the world's first 50 kg-class deep space micro-spacecraft PROCYON. Its mission objective is to demonstrate a micro-spacecraft bus technology for deep space exploration and proximity flyby to asteroids performing optical measurements. PROCYON was launched into the Earth departure trajectory on December 3, 2014, together with Japanese asteroid sample return mission Hayabusa-2. PROCYON completed the bus system demonstration mission in its interplanetary flight. Currently, we are developing two self-contained 6U CubeSats for the rideshare opportunity on the USA's SLS Artemis-1 mission, one of which (EQUULEUS) will fly to a libration orbit around Earth—Moon L2 point and perform scientific observations of the Earth and the Moon, and the other (OMOTENASHI) is planning to perform "semi-hard" landing on the moon by using a solid rocket motor onboard. Also, we are studying the sub-spacecraft (B1) of ESA's Comet Interceptor, which conducts multiple observation of a Long Period Comet. We are also seeking the possibility of CubeSats by taking advantage of its low-cost, risk-tolerable and physically-small feature. We are studying several other CubeSat and Mirco-sat deep space missions in Japan, and this paper overviews the Japanese achievements and future plans of CubeSats and Micro-Sats for deep space exploration.