BepiColombo is Europe’s first mission to Mercury. Launched on 20 October 2018, it is on a seven-year journey to the smallest and least explored terrestrial planet in our Solar System.
The mission consists of three spacecraft: ESA's Mercury Planetary Orbiter (MPO) to study the surface and internal composition of the planet, the Japanese Space Agency's (JAXA) Mercury Magnetospheric Orbiter (MMO) to investigate its magnetosphere, and the Mercury Transfer Module which carries them there.
ESA is responsible for the overall mission design, and for the operation of the composite spacecraft up to the insertion of the MPO and MMO into their orbits.
The mission is one of the most challenging long-term planetary projects, because Mercury's proximity to the Sun makes it difficult for a spacecraft to reach the planet, and also to survive in the harsh environment there.
On its long way to Mercury, the spacecraft must brake against the Sun's gravity, which increases with proximity to the Sun – rather than accelerate away from it, as is the case with journeys to the outer solar system. BepiColombo will accomplish this with the help of a series of planetary flybys.
During the cruise, the team at ESOC in Darmstadt will coordinate operation of the full composite spacecraft using ESA's Estrack 35-m deep-space antennas. The Cebreros ground station will provide telecommanding visibility for some 8 hours daily; a cross-support agreement with JAXA ensures that the Japanese Usuda Deep Space Centre's 64 m-diameter station can be also be used as back-up during critical phases and in case of problems.
After arrival at Mercury and separation of the MMO by spin ejection, Japan's JAXA Sagamihara Space Operation Centre, using the Usuda station in Nagano, will take over the operation of the MMO once it is in orbit around Mercury, while ESOC will remain in charge of the MPO spacecraft.
The information obtained when BepiColombo arrives will help improve our understanding not only of the composition and history of Mercury, but also the history and formation of the inner planets of the Solar System, including Earth.