BepiColombo is a world-class science mission led by the European Space Agency (ESA) in close collaboration with the Japan Aerospace Exploration Agency (JAXA). It will be the first mission to orbit Mercury with two spacecraft, with ESA’s Mercury Planetary Orbiter (MPO) and JAXA’s Mercury Magnetospheric Orbiter (Mio) orbiting the planet at the same time. 

The 'arrival phase' began with the separation of the Mercury Transfer Module (MTM) from the spacecraft stack on 3 September 2026. The composite spacecraft will enter orbit around Mercury on 21 November 2026, and MPO and Mio will separate from each other on 9–10 December 2026. The mission’s science phase is set to begin in April 2027. 

Since separating from MTM on 3 September, ESA's Mercury Planetary Orbiter (MPO) must take charge of its – and the still-attached Japanese Mio science orbiter's – final approach to Mercury. On 24 September, MPO tested its axial thrusters for the first time in this new configuration.

For 8 minutes and 42 seconds, the thrusters fired as the ESA Mission Control Team at ESOC closely monitored power, temperature, pressure, acceleration and Doppler data received via ESA's Cebreros deep-space antenna in Spain.

This resulted in a precise push of 11.4 m/s, the first planned trajectory correction since MTM separation. This demonstrates the spacecraft's ability to stay on course for its next major milestone. A number of similar small trajectory correction slots are planned for precise targeting prior to the main orbit insertion sequence in November. 

The BepiColombo team held a press briefing on 9 September 2026 at the Europlanet Science Congress (EPSC2026) in The Hague, Netherlands. The briefing was published online last week: Watch the EPSC2026 press briefing

The briefing gave an update on the status of the spacecraft following MTM separation (3 September), and provided an overview of the next steps during this exciting time in the BepiColombo mission. The speakers were: Santa Martinez Sanmartin, BepiColombo Mission Manager; Ignacio Tanco, Head of ESA's Inner Solar System Missions Unit; Geraint Jones, Lead ESA BepiColombo Project Scientist; and Go Murakami, JAXA BepiColombo Project Scientist.

As a reminder, on 31 August 2026 ESA arranged a press briefing as well, a few days before MTM's separation. Rewatch it here. 

Read the story of MTM's separation
Rewatch ESA's livestream

14:52 BST / 15:52 CEST 
Acquisition of signal via two Estrack deep space antennas, in Cebreros (Spain) and Malargüe (Argentina), have confirmed the successful separation of BepiColombo's Mercury Transfer Module (MTM) from the spacecraft stack. Current telemetry indicates all systems are nominal, and MPO's solar panels are charging the spacecraft's batteries. 

Behind today's success are years of preparation by teams across the BepiColombo mission. Executing a critical separation more than 200 million kilometres from Earth demands precise planning, navigation and commanding, with no opportunity for real-time intervention.

After nearly eight years in space and billions of kilometres travelled, BepiColombo's two science orbiters, ESA's MPO and JAXA's Mio, are now on their way towards orbit insertion around Mercury. MPO will power the spacecraft stack until Mio separates on 9–10 December 2026. 

13:41 BST / 14:41 CEST  
We have detected the preliminary Doppler signal indicating that MTM has separated from the BepiColombo spacecraft stack. The Doppler signal is a variation in the radio frequency established between Earth and the spacecraft. When the spacecraft changes velocity, the frequency of the signal changes. It is the same principle that makes us hear a change in pitch in the siren sound when an ambulance moves towards us or away from us. 

The initial Doppler signal is consistent with the planned MTM separation sequence. For full confirmation of the separation being successful, we're awaiting a signal from the MPO spacecraft at around 14:53 BST / 15:53 CEST.

13:00 BST / 14:00 CEST
BepiColombo's Mercury Transfer Module should have now separated from the spacecraft, a key step in the mission's journey towards orbiting Mercury. Now expecting acquisition of signal confirming separation no earlier than 14:53 BST / 15:53 CEST.

12:45 BST / 13:45 CEST
ESA's livestream has started! You can watch it here. 

Information about ESA's livestream

11:03 BST / 12:03 CEST
"Roll call completed, GO for separation" – the Mission Control Team has the green light to proceed with BepiColombo's MTM separation. The spacecraft is checked and configured, the ground stations are prepared, and the team at ESA’s European Space Operations Centre (ESOC) is ready.