A confirmed milestone
ESA reported on 7 September 2026 that BepiColombo’s Mercury Transfer Module separated successfully on 3 September. Mission control received confirmation at 15:49 CEST after the signal travelled roughly 200 million kilometres to Earth.
What the module accomplished
The transfer module carried the ESA–JAXA spacecraft stack from Earth toward Mercury. Its solar arrays powered ion thrusters that produced gentle, sustained thrust while using much less propellant than a comparable series of chemical burns.
Why Mercury is difficult
Travelling inward is not simply a matter of falling toward the Sun. A spacecraft must shed orbital energy while controlling heat and trajectory. BepiColombo travelled about 9.9 billion kilometres and used nine planetary flybys before reaching this arrival phase.
Separation is not arrival
The successful event is the first step in a sequence, not completed orbit insertion. ESA says chemical-propulsion manoeuvres will refine the trajectory, Mercury orbit insertion is planned for 21 November, and the two scientific spacecraft will later separate into their own orbits.
Science still lies ahead
The mission is expected to begin coordinated scientific investigations in 2027. Its instruments are designed to study Mercury’s surface, interior, magnetic field and surrounding environment. Those results cannot be claimed before observations are made and analysed.
Engineering under uncertainty
ESA also notes that teams redesigned part of the route after reduced solar-array power affected the transfer module. The successful separation shows one recovery milestone, while future manoeuvres remain essential.
Primary source
Read ESA’s mission update. Accessed 12 September 2026.