The joint ESA and JAXA BepiColombo spacecraft has officially initiated its arrival phase at Mercury, following the successful separation of its Mercury Transfer Module on September 3, 2026, after a 7.2-year journey across billions of kilometers, according to mission controllers. This critical milestone sets the stage for the composite spacecraft to enter orbit around the innermost planet on November 21, 2026, marking a major step for the first European-led mission to Mercury.
BepiColombo Arrival Phase Kicks Off With Successful Module Separation
Mission controllers confirmed the separation of the Mercury Transfer Module (MTM) from the rest of the spacecraft stack on September 3, 2026. According to the European Space Agency (ESA), confirmation arrived via two deep-space tracking antennas located in Spain and Argentina, which picked up signals validating the physical split.
Telemetry data reviewed by engineering teams showed all onboard systems functioning normally. Furthermore, the Mercury Planetary Orbiter’s (MPO) solar panels are already actively charging the spacecraft’s batteries.
“The arrival phase begins with the separation of MTM from the spacecraft stack on September 3, 2026,” members of the BepiColombo team stated.
This maneuver carried significant operational risk. Operating more than 200 million kilometers from Earth meant that real-time troubleshooting was physically impossible, requiring exhaustive advance planning by the combined ESA and JAXA teams.
Trajectory and Upcoming Orbital Insertion Milestones
Blasting off originally from Europe’s Spaceport in Kourou, French Guiana, on October 20, 2018, BepiColombo utilized a complex cruise configuration. During its multi-year trek, the spacecraft executed one flyby of Earth, two of Venus, and six of Mercury.
Following the departure of the transfer module, the MPO and Mio craft are now proceeding toward Mercury orbit insertion, with the MPO supplying power to the combined assembly until the two orbiters eventually part ways.
According to mission timelines, the composite spacecraft will formally enter orbit around Mercury on November 21, 2026. Following that, the MPO and Mio orbiters will separate from each other on December 9-10, 2026, paving the way for the mission’s official science phase to begin in April 2027.
Did you know? BepiColombo is named after the Italian mathematician and engineer Giuseppe (Bepi) Colombo. Professor Colombo was the initial researcher to recognize that an unexpected resonance accounts for Mercury spinning on its axis three complete times for every two orbits it completes around the Sun. He additionally advised NASA on utilizing a Venus gravity-assist flyby to put the Mariner 10 probe into a solar trajectory enabling three separate Mercury flybys across 1974-5.
Dual-Orbiter Strategy for Studying the Inner Planet
Serving as the inaugural European venture to Mercury, BepiColombo also stands out as the first endeavor to dispatch a pair of spacecraft simultaneously for coordinated, multi-faceted observations of the planet and its active environment.
The system comprises two distinct spacecraft components: the Mercury Planetary Orbiter (MPO) provided by ESA alongside the Mercury Magnetospheric Orbiter (MMO, also designated as ‘Mio’) built by JAXA.
Frequently Asked Questions
When will BepiColombo enter orbit around Mercury?
According to mission schedules, the spacecraft will enter orbit around Mercury on November 21, 2026.
What was the purpose of the September 2026 maneuver?
Mission controllers executed the separation of the Mercury Transfer Module (MTM) from the rest of the stack on September 3, 2026, officially initiating the arrival phase.
When does the main science phase begin?
The science phase is scheduled to begin in April 2027, following the separation of the two individual orbiters in December 2026.
Who operates the two orbiters?
The mission is a science mission led by ESA in close collaboration with JAXA. The system comprises two distinct spacecraft components: the Mercury Planetary Orbiter (MPO) provided by ESA alongside the Mercury Magnetospheric Orbiter (MMO, also designated as ‘Mio’) built by JAXA.
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