Bepicolombo is a joint European and Japanese mission to Mercury, consisting of two spacecraft: the Mercury Planetary Orbiter (MPO) built by Airbus Defence and Space for ESA, and the Mercury Magnetospheric Orbiter (MMO) developed by JAXA. The mission was launched on 20 October 2018 from Kourou aboard an Ariane 5 rocket.
The mission’s primary goal is to studyMercury’s surface, interior and environment. Bepicolombo will make numerous measurements during its one-year nominal mission, which can be extended to two years.
The orbiters will also search for evidence of water ice at the poles of Mercury, which would help explain how the planet formed and evolved.
Bepicolombo consists of two orbiters: MPO and MMO. MPO is designed to study Mercury’s surface geology, composition and internal structure. It will also investigate the planet’s exosphere and magnetosphere. MMO will focus on studying Mercury’s magnetosphere in detail.
Both orbiters are equipped with solar panels to generate electrical power, as well as thrusters for manoeuvring in space. They also carry antennas for communicating with Earth, as well as scientific instruments for taking measurements.
The MPO has a mass of 1095 kg and is 693 kg when fuelled; it is 7 m long with its solar panels deployed, but only 3 m wide folded up against its body. The MMO has a mass of 820 kg; it too is 693 kg when fuelled and 7 m long with solar panels deployed, but only 2 m wide when folded up against its body. Together, they form what is called a “stack” configuration during launch – this means that they are attached to each other like steps on a staircase, with MPO on top of MMO so that both orbiters can be deployed after launch using a single set of mechanisms and pyrotechnic devices..