Overview
- The Mercury Transfer Module successfully separated from the two orbiters on Thursday, Sept. 3, 2026, and mission control received telemetry confirming the remaining stack was in the expected configuration and generating power.
- The connected orbiters will be captured into a wide Mercury orbit on November 21, 2026, then separate from one another about three weeks later with routine science operations planned to begin in April 2027.
- Engineers extended the cruise after a 2024 problem in which the transfer module’s solar arrays and ion thrusters underdelivered, and the team revised the trajectory and timeline to preserve the mission objectives.
- The twin spacecraft carry complementary payloads with ESA’s Mercury Planetary Orbiter mapped for surface and interior studies and JAXA’s Mio dedicated to magnetosphere and magnetic‑field measurements.
- Arrival will be a months‑long, finely staged sequence of many small maneuvers and autonomous operations in extreme heat and radiation, a profile that increases risk but also enables detailed orbit shaping and prolonged science coverage.