BepiColombo
BepiColombo is a joint European Space Agency (ESA) and Japan Aerospace Exploration Agency (JAXA) mission to investigate Mercury and its space environment. Launched in October 2018, it consists of ESA's Mercury Planetary Orbiter (MPO) and JAXA's Mercury Magnetospheric Orbiter (Mio), which travelled together with a transfer module. Following separation of the transfer module in September 2026, the spacecraft are approaching Mercury; orbit insertion is planned for November 2026, with routine science observations scheduled to begin in 2027.
Mission and spacecraft
BepiColombo is an international planetary mission led jointly by ESA and JAXA. It launched from Europe's Spaceport in Kourou, French Guiana, on 20 October 2018 aboard an Ariane 5 rocket. The mission was assembled as a transfer module carrying two scientific orbiters: ESA's Mercury Planetary Orbiter (MPO) and JAXA's Mercury Magnetospheric Orbiter (Mio), also known as the Mercury Magnetospheric Orbiter (MMO). The transfer module provided propulsion during the long journey through the inner Solar System.
Scientific objectives
The orbiters are designed to study Mercury's interior, surface, exosphere and magnetosphere, including the planet's magnetic field and the interaction between the solar wind and Mercury's environment. The spacecraft carry complementary scientific instruments so observations from the two orbiters can be compared. Studying Mercury can help researchers investigate how rocky planets formed and evolved, and how a planet close to the Sun maintains a magnetic field and a thin atmosphere.
Arrival and operations
BepiColombo used a multi-year, fuel-efficient interplanetary trajectory and conducted several flybys of Earth, Venus and Mercury before reaching its destination. ESA reported that the Mercury Transfer Module separated from the spacecraft stack on 3 September 2026, beginning the mission's arrival phase. According to ESA's published schedule on 30 October 2026, the composite spacecraft is expected to enter Mercury orbit on 21 November 2026; MPO and Mio are scheduled to separate from one another in December 2026, and routine science operations are planned to begin in April 2027. These are planned milestones, not completed events.
Why Mercury matters
Mercury is the smallest planet and the closest to the Sun. Its high density, large metallic core, magnetic field and polar regions that can remain in permanent shadow pose questions about planetary formation and evolution. BepiColombo's paired orbiters will examine the planet and its surrounding space from different observational perspectives, complementing earlier spacecraft explorations by Mariner 10 and NASA's MESSENGER.
Key facts
- Agencies
- European Space Agency (ESA) and Japan Aerospace Exploration Agency (JAXA)
- Launch
- 20 October 2018, aboard an Ariane 5 rocket
- Science orbiters
- ESA's Mercury Planetary Orbiter (MPO) and JAXA's Mercury Magnetospheric Orbiter (Mio/MMO)
- Transfer module separation
- 3 September 2026
- Planned Mercury orbit insertion
- 21 November 2026 (ESA schedule as of 30 October 2026)
- Planned start of routine science
- April 2027 (ESA schedule as of 30 October 2026)
- Main research areas
- Mercury's interior, surface, exosphere, magnetic field and magnetosphere
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References
- 1.BepiColombo
European Space Agency · other · reliability: unverified · retrieved 30 October 2026
Supports: Mission overview, launch, spacecraft components and current high-level schedule.
- 2.Latest updates: BepiColombo's arrival at Mercury
European Space Agency · other · reliability: unverified · retrieved 30 October 2026
Supports: Mission partnership and spacecraft, transfer-module separation on 3 September 2026, and ESA's planned orbit insertion, orbiter separation and science-phase dates.
- 3.Mercury Magnetospheric Orbiter MIO / BepiColombo
Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency · other · reliability: unverified · retrieved 30 October 2026
Supports: JAXA's Mio spacecraft, the joint mission structure and objectives concerning Mercury's magnetic field, magnetosphere, interior and surface.
- 4.BepiColombo - Mission Overview and Science Goals
Space Science Reviews, Springer Nature · other · reliability: unverified · retrieved 30 October 2026
Supports: Peer-reviewed mission overview, ESA–JAXA partnership, launch, two-orbiter architecture and scientific goals.
References are suggested by the research engine and may be incomplete. Unverified URLs are omitted rather than guessed.
Article history
- Version 130 October 2026 · EditorCreated by Zapia