BepiColombo
BepiColombo is a joint mission of the European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA) to the planet Mercury. The mission comprises two satellites launched together: the Mercury Planetary Orbiter (MPO) and Mio (Mercury Magnetospheric Orbiter, MMO). The mission will perform a comprehensive study of Mercury, including characterization of its magnetic field, magnetosphere, and both interior and surface structure. It was launched on an Ariane 5 rocket on 20 October 2018 at 01:45 UTC, with an arrival at Mercury planned for on 5 December 2025, after a flyby of Earth, two flybys of Venus, and six flybys of Mercury. The mission was approved in November 2009, after years in proposal and planning as part of the European Space Agency's Horizon 2000+ programme; it is the last mission of the programme to be launched. Names BepiColombo is named after Giuseppe "Bepi" Colombo (1920–1984), a scientist, mathematician and engineer at the University of Padua, Italy, who first proposed the interplanetary gravity assist manoeuvre used by the 1974 Mariner 10 mission, a technique now used frequently by planetary probes. Mio, the name of the Mercury Magnetospheric Orbiter, was selected from thousands of suggestions by the Japanese public. In Japanese, Mio means a waterway, and according to JAXA, it symbolizes the research and development milestones reached thus far, and wishes for safe travel ahead. JAXA said the spacecraft will travel through the solar wind just like a ship traveling through the ocean. In Chinese and Japanese, Mercury is known as the "water star" (水星) according to wǔxíng. Following its Earth flyby in April 2020, BepiColombo was briefly mistaken for a near-Earth asteroid, receiving the provisional designation . Mission The mission involves three components, which will separate into independent spacecraft upon arrival at Mercury. Mercury Transfer Module (MTM) for propulsion, built by ESA. Mercury Planetary Orbiter (MPO) built by ESA. Mercury Magnetospheric Orbiter (MMO) or Mio built by JAXA. During the launch and cruise phases, these three components are joined together to form the Mercury Cruise System (MCS). The prime contractor for ESA is Airbus Defence and Space. ESA is responsible for the overall mission, the design, development assembly and test of the propulsion and MPO modules, and the launch. The two orbiters, which are operated by mission controllers based in Darmstadt, Germany, were successfully launched together on 20 October 2018. The launch took place on Ariane flight VA245 from Europe’s Spaceport in Kourou, French Guiana. The spacecraft will have a seven-year interplanetary cruise to Mercury using solar-electric propulsion (ion thrusters) and gravity assists from Earth, Venus and eventual gravity capture at Mercury. ESA's Cebreros, Spain ground station is planned to be the primary ground facility for communications during all mission phases. Expected to arrive in Mercury orbit on 5 December 2025, the Mio and MPO satellites will separate and observe Mercury in collaboration for one year, with a possible one-year extension. The orbiters are equipped with scientific instruments provided by various European countries and Japan. The mission will characterize the solid