According to European Space Agency (ESA), BepiColombo, which consists two orbiters was launched from Ariane 5 rocket to study Mercury
A Mercury-bound science mission from the European Space Agency (ESA) and Japan Aerospace Exploration Agency (JAXA) began a seven-year journey to Mercury. On October 19, 2018, Ariane 5 rocket launched the BepiColombo mission from the European Spaceport in Kourou, French Guiana at 9:45 p.m. Eastern. The spacecraft will travel 9-billion kilometers to reach Mercury and contains four parts: two science orbiters, their carrier unit, and a sunshield with a total payload of 4,100-kilogram. ESA confirmed signal acquisition shortly after the spacecraft separated from Ariane 5.
The spacecraft’s journey includes nine planetary flybys for gravitational assists — one of Earth, two of Venus and six by Mercury, which will enable safe arrival in orbit around Mercury. Once in Mercury’s orbit, BepiColombo’s carrier spacecraft is expected to release ESA’s Mercury Planetary Orbiter and JAXA’s Mercury Magnetospheric Orbiter that will mark the beginning of a one-year science mission. The mission marks the first joint mission of JAXA with ESA and both space agencies’ first mission to Mercury. The mission that began in 2000 was on the brink of cancellation as it grew too large to fit in a Soyuz rocket. In 2009, ESA approved the redesigned mission that featured systems, which were optimized for the extreme temperatures near Mercury.
ESA’s Mercury Planetary Orbiter is tasked to study the surface of Mercury using a suite of 11 instruments. JAXA’s Mercury Magnetospheric Orbiter will study the planet’s magnetosphere and its interactions with the sun with the help of five instruments onboard. Airbus Defence and Space is the major contractor for ESA’s part of BepiColombo. JAXA collaborated with Japan-based NEC Corp for its Mercury Magnetospheric Orbiter. BepiColomobo includes contribution from companies such as QinetiQ, a U.K-based company that offered new, highly efficient electric propulsion system to slow the spacecraft and Azur Space, a Germany-based manufacturer that offered solar cells capable of generating power while enduring higher than normal temperatures.