BepiColombo

BepiColombo
Mercury Planetary Orbiter and Mercury Magnetospheric Orbiter
The BepiColombo spacecraft stack on 5 July 2017. From bottom to top: MTM, MPO, and Mio. Solar arrays are stowed, and MOSIF is not shown.
Mission typePlanetary science
Operator
COSPAR ID2018-080A
SATCAT no.43653
Websitescience.esa.int/bepicolombo
Mission durationCruise: 7 years, 2 month, 18 days (planned) 8 years, 1 month, 1 day (actual)
Science phase: 1 year (planned)
7 years, 10 months and 25 days (in progress)
Spacecraft properties
Manufacturer
Launch mass4,100 kg (9,000 lb)
BOL massMPO: 1,230 kg (2,710 lb)
Mio: 255 kg (562 lb)
Dry mass2,700 kg (6,000 lb)
DimensionsMPO: 2.4 m × 2.2 m × 1.7 m (7 ft 10 in × 7 ft 3 in × 5 ft 7 in)
Mio: 1.8 m × 1.1 m (5 ft 11 in × 3 ft 7 in)
PowerMPO: 150 watts
Mio: 90 watts
Start of mission
Launch date20 October 2018, 01:45 UTC
RocketAriane 5 ECA (VA245)
Launch siteCentre Spatial Guyanais, ELA-3
ContractorArianespace
Mercury orbiter
Spacecraft componentMercury Planetary Orbiter (MPO)
Orbital insertion21 November 2026 (planned)
Orbital parameters
Perihermion altitude480 km (300 mi)
Apohermion altitude1,500 km (930 mi)
Inclination90,0°
Mercury orbiter
Spacecraft componentMercury Magnetospheric Orbiter (Mio/MMO)
Orbital insertion10 December 2026 (planned deployment from MPO)
Orbital parameters
Perihermion altitude590 km (370 mi)
Apohermion altitude11,640 km (7,230 mi)
Inclination90.0°

ESA insignia (2020s)

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 orbiters: the Mercury Planetary Orbiter (MPO), built and operated by ESA, and Mio (Mercury Magnetospheric Orbiter, MMO), built and operated by JAXA. Together the satellites will perform a comprehensive study of Mercury, including characterization of its magnetic field, magnetosphere, and both interior and surface structure.

During the cruise phase to reach Mercury, the orbiters were in a stacked configuration with two additional components: the Mercury Transfer Module (MTM), which provided power and solar electric propulsion for the cruise, and the Magnetospheric Orbiter Sunshield and Interface (MOSIF), which protects Mio from the harsh solar radiation until it is deployed. MTM was jettisoned before orbit insertion at Mercury, whereas MOSIF will be detached from MPO after the Japanese orbiter is deployed.

In 2017 the spacecraft's cost was estimated at €1.65 billion (US$1.86 billion). It was launched on an Ariane 5 rocket on 20 October 2018, with Mercury orbit insertion planned for December 2025, after a flyby of Earth, two flybys of Venus, and six flybys of Mercury. In 2024, due to a power-related anomaly limiting the thrust levels on its solar electric propulsion system, Mercury arrival was delayed to November 2026.