BepiColombo Euro-Japan Joint mission to Mercury: MMO Project Status

BepiColombo is a ESA-JAXA joint mission to Mercury with the aim to understand the process of planetary formation and evolution in the hottest part of the proto-planetary nebula as well as to understand similarities and differences between the magnetospheres of Mercury and Earth. The baseline mission consists of two spacecraft, i.e. the Mercury Planetary Orbiter (MPO) and the Mercury Magnetospheric Orbiter (MMO). The two orbiters will be launched in 2014 by an Ariane-5 and arrive at Mercury in 2020. JAXA is responsible for the development and operation of MMO, while ESA is responsible for the development and operation of MPO as well as the launch, transport, and the insertion of two spacecraft into their dedicated orbits. JAXA has made conceptual design of the MMO spacecraft system (including the interface with the cruising composite system in collaboration with ESA) with model payload. MMO is designed as a spin-stabilized spacecraft to be placed in a 400 km x 12000 km polar orbit. The spacecraft will accommodate instruments mostly dedicated to the study of the magnetic field, waves, and particles near Mercury. Selection of the PI responsible instruments was finished on 2004. Subsystem level Critical Design Review(CDR) for MMO project was held during Mar. 2010 - May 2011. MMO system level first part of CDR was held on June 2011. ESA BepiColombo project is now working for preparation of CDR which will be held middle of 2012. Stand alone test with Mechanical Test Model(MTM) test and Thermal Test Model(TTM) was successfully finished on Nov. 2010. 10 solar constant thermal test with MOSIF (MMO sunshield interface) was successfully finished on Dec. 2010. MMO TTM is under refurbishing to the MTM for attending the stack level MTM test will be held from early next year. Electrical and Mechanical interface test (EIC/MIC) for MMO flight hardware has been started. MMO stand alone Flight Model (FM) AIV will be started from spring 2012. 8th BepiColombo science working team (SWT) meeting, which discusses science related matters, will be held on Sep. 2009 following to the MESSENGER-BepiColombo Joint Workshop. In this paper, we will report the latest information of MMO project status.