Overview
- The Mercury Transfer Module separated from the twin science orbiters on Thursday, Sept. 3, and mission controllers received delayed radio confirmation that the separation and telemetry were nominal.
- The joined orbiters remain attached as a stack and are en route to a planned Mercury orbital capture on Nov. 21, 2026, after which the pair will carry out 16 orbit‑shaping maneuvers.
- If insertion and follow-up burns go as planned, JAXA’s Mio will be released first around Dec. 9–10 into a highly elliptical magnetosphere-mapping orbit, and ESA’s MPO will follow into a low polar mapping orbit in mid-December to March 2027.
- Engineers warn the arrival is one of the most technically demanding sequences ever attempted because the probes must act autonomously under intense heat and radiation and about a 30-minute one-way signal delay to Earth.
- BepiColombo used low-thrust electric propulsion and nine gravity assists over nearly eight years to reach Mercury, and a 2024 solar-panel/thruster issue forced a lower-thrust trajectory that delayed arrival but preserved the mission; the two orbiters will map Mercury’s surface and interior and study its magnetosphere when science begins in April 2027.