BepiColombo Begins Mercury Arrival After Mercury Transfer Module Separates

The European Space Agency's BepiColombo Mission Control Team received confirmation on 3 September 2026 that the spacecraft's Mercury Transfer Module (MTM) had successfully separated from the spacecraft stack, marking the first step of the joint ESA–JAXA mission's long-awaited arrival at Mercury. Over the past eight years, BepiColombo has travelled 9.9 billion kilometres through the inner Solar System and completed nine planetary flybys to reach this milestone.

The separation is the first in a sequence of manoeuvres that will see BepiColombo become the first mission to place two spacecraft in orbit around Mercury, in December 2026. ESA describes the mission's Mercury arrival phase as one of the most complex planetary arrival sequences it has ever attempted. Mission controllers gave the official "GO" for separation at 12:00 CEST (Central European Summer Time), with the manoeuvre expected around 14:00 CEST — followed by a nearly two-hour wait for confirmation to arrive from 200 million kilometres away.

A preliminary Doppler signal at 14:20 CEST gave the first indication that separation had taken place. "We heard it loud and clear in the voice loop... that MTM had separated. After all this waiting and preparation, we all looked at each other and hugged. It was a very powerful moment," said Emmanuela Bordoni, ESA BepiColombo B-shift Spacecraft Operations Manager. Full confirmation, an acquisition of signal, arrived at 15:49 CEST via ESA's Estrack deep-space antennas.

The car-sized MTM carried two 15-metre-long solar wings that powered the spacecraft stack and propelled it using solar electric propulsion — a system that turns xenon gas into plasma expelled through four ion thrusters, delivering gentle but continuous thrust for days, weeks or months while using far less propellant than chemical propulsion. With no antenna or onboard computer of its own, the now-inoperable module will remain in a stable orbit around the Sun.

MTM also carried three monitoring cameras that documented BepiColombo's journey with daily snapshots throughout the cruise phase, an eight-year photo diary whose final images are now archived in ESA's Planetary Science Archive.