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BepiColombo is a joint mission of the European Space Agency (ESA) and JAXA to the planet Mercury. The mission comprises two satellites to be launched together: the Mercury Planetary Orbiter (MPO) and the Mercury Magnetospheric Orbiter (MMO). The mission will perform a comprehensive study on Mercury, including its magnetic field, magnetosphere, interior structure and surface. It is scheduled to launch in January 2017.〔 The mission was approved in February 2007 as part of the Cosmic Vision programme.〔 == Mission == BepiColombo is named after Giuseppe (Bepi) Colombo (1920–1984), scientist, mathematician and engineer at the University of Padua, Italy, who first implemented the interplanetary gravity-assist maneuver during the 1974 ''Mariner 10'' mission, a technique now commonly used by planetary probes. The mission involves three components:〔(Hajime Hayakawa: BepiColombo Mercury Magnetospheric Orbiter (MMO) )〕 * Mercury Transfer Module (MTM) for propulsion, built by ESA * Mercury Planetary Orbiter (MPO) built by ESA * Mercury Magnetospheric Orbiter (MMO) built by JAXA. The prime contractor for ESA is EADS Astrium.〔(【引用サイトリンク】 BepiColombo To Enter Implementation Phase )〕 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 are planned to be launched together on an Ariane 5 launch vehicle in January 2017. The spacecraft will have a six-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 35-metre ground station is planned to be the primary ground facility for communications during all mission phases. Arriving in Mercury orbit in 1 January 2024, MMO and MPO satellites will then separate and observe Mercury in collaboration for 1 year, with a possible 1-year extension.〔 The orbiters will be equipped with scientific instruments provided by various European countries and Japan. It will characterise the huge liquid iron core (¾ of the planet radius) and will complete gravity and magnetic field mappings. Russia will provide a gamma ray and neutron spectrometers to verify the existence of water ice in polar craters that are permanently in shadow from the Sun's rays. Mercury is too small and hot for its gravity to retain any significant atmosphere over long periods of time; it does have a "tenuous surface-bounded exosphere" containing hydrogen, helium, oxygen, sodium, calcium, potassium and others. Its exosphere is not stable; atoms are continuously lost and replenished from a variety of sources, and the mission will also study its composition and dynamics, including generation and disappearance. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「BepiColombo」の詳細全文を読む スポンサード リンク
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