Current Status of Japanese Participation to Jupiter Icy Moons Explorer "JUICE"

JUICE is an ESA's L-class mission to Explore Jupiter Icy Moons. The science objectives of JUICE is to understand (1) emergence of habitable worlds around gas giants and (2) Jupiter system as an archetype for gas giants. JUICE was mission adopted in November 2014. JUICE will be launched by Arian-5. After 7.5 years of interplanetary transfer and Earth-Venus-Earth-Earth gravity assists JUICE will be inserted into an orbit around Jupiter in January 2030. JUICE will make observation of all the three Jupiter icy Moons that potentially have subsurface ocean under the icy crust. After inserted into Ganymede orbit in 2032, JUICE will make detailed observation of the largest Icy Moon in the solar system. Three Japanese groups were selected to provide part of the three science instruments RPWI, GALA, and PEP/JNA. Two Japanese groups were also selected as science Co-I of two instrument groups JANUS and J-MAG. JUICE is the first mission for ISAS/JAXA to participate to foreign large science mission as a junior partner who will provide part of the science instruments. Taking into account all the data to be obtained by 5 instruments that JUICE-JAPAN will participate, Japanese team will be able to contribute to most of the major science objectives relating with planet Jupiter (JANUS), Jupiter magnetosphere (PEP/JNA, RPWI, and J-MAG), and Icy Moons (GALA, J-MAG, and JANUS). JUICE-JAPAN Working Group (WG) was established in September 2013. JUICE-JAPAN WG submitted a proposal for ISAS/JAXA small project in February 2014. JUICE-JAPAN WG passed the MDR in September 2014. JUICE-JAPAN passed the ISAS SRR that was held in April 2015 and also passed the ISAS project preparation review that was held in May 2015. Currently JUICE-JAPAN is an ISAS pre-project. In the future, SDR is scheduled in the end of 2015, PDR is scheduled in 2016 and CDR is scheduled in 2017. JUICE is a long-term mission that will be completed about 20 years from now. It is quite important to take place a necessary change of generations in order to make the participation to JUICE a success.