Summary
ESA says BepiColombo is scheduled to separate its Mercury Transfer Module on 3 September 2026, beginning the mission’s Mercury arrival phase. Mercury orbit insertion is planned for November, followed by separation of the ESA and JAXA science orbiters in December.
ESA says the BepiColombo spacecraft is scheduled to separate its Mercury Transfer Module (MTM) on 3 September 2026. At a media briefing on 31 August, the agency described the separation as a critical milestone marking the start of the mission’s Mercury arrival phase.
The separation is one step in a sequence that continues over the following months. ESA listed Mercury orbit insertion for November 2026, with the mission’s two science orbiters—the agency’s MPO and JAXA’s Mio—scheduled to separate in December.
A transition toward Mercury orbit
The MTM separation, orbit insertion and release of the science orbiters are distinct events in ESA’s announced timeline. The 3 September milestone is not the arrival in orbit: ESA places that manoeuvre in November, with the two orbiters separating later, in December.
BepiColombo is a joint ESA-JAXA mission. Its two orbiters are intended to study Mercury, and ESA says they will be only the second and third spacecraft to orbit the planet. The agency describes Mercury as the least explored planet in the inner Solar System, noting that its proximity to the Sun makes it especially difficult for an orbiter to reach.
What the mission timeline sets up
The December separation will mark the point at which ESA’s and JAXA’s orbiters part ways as separate spacecraft. The briefing page says the mission is preparing to begin operations around Mercury and that the mission offers scientific opportunities there; it does not provide specific findings or measurements, since the scheduled arrival milestones were still ahead at the time of the briefing.
ESA presented the schedule alongside an update on mission status and operational challenges. Its published briefing summary identifies the key dates and sequence, rather than detailing the technical procedures for the MTM separation or the later orbit-insertion manoeuvre.