Mission

BepiColombo

ESA and JAXA mission to Mercury, launched in October 2018, that splits into two orbiters to study the planet together; science is to begin in April 2027.

BepiColombo is a European Space Agency mission to Mercury, built in close collaboration with the Japan Aerospace Exploration Agency (JAXA).[1] It is the second mission ever to orbit Mercury, and the first to do so with two spacecraft at once.[2][1]

The journey

Mercury is close to the Sun and harder for an orbiter to reach than Saturn.[2] BepiColombo launched on an Ariane 5 rocket on 20 October 2018 and flew past Mercury six times between October 2021 and January 2025 on its way into orbit.[2] On 3 September 2026 it released its transfer module, the stage that carried it across the inner solar system.[1]

Two orbiters

BepiColombo was planned to enter orbit around Mercury on 21 November 2026, and its two spacecraft, ESA's Mercury Planetary Orbiter and JAXA's Mercury Magnetospheric Orbiter, Mio, to separate on 9 and 10 December 2026.[1] The science phase is planned to begin in April 2027.[1]

Why Mercury

Mercury is the least explored planet of the inner solar system, and learning about it sheds light on the history of the whole solar system.[2] The mission is to address questions such as why there is ice in the polar craters of so hot a planet, why Mercury has a magnetic field, and what the mysterious hollows on its surface are.[2]

Milestones

  1. October 20, 2018
    Launch on Ariane 5
  2. September 3, 2026
    Drops its transfer module
  3. November 21, 2026
    Enters orbit around Mercury
  4. December 9–10, 2026
    The two orbiters, MPO and Mio, separate
  5. April 2027 expected
    Science phase begins

Dates marked expected are agency estimates.

All missions and what each does next

Sources

  1. [1]European Space Agency, Latest updates: BepiColombo's arrival at Mercury — esa.int, retrieved October 26, 2026
  2. [2]European Space Agency, BepiColombo — esa.int, retrieved October 26, 2026

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