BepiColombo begins its final approach to Mercury
After eight years in space, ESA and JAXA are moving BepiColombo into the decisive arrival phase; orbit insertion is planned for November, with science to follow in 2027.
The 60-second version
BepiColombo has entered its final Mercury-arrival sequence after a confirmed transfer-module separation.
Key points
- ESA and JAXA are sending two science orbiters to operate around Mercury.
- Orbit insertion is planned for 21 November 2026, followed by orbiter separation in December.
- The mission’s scientific operations are scheduled for April 2027, so the key measurements are still ahead.
Verdict. This is a major confirmed milestone, but not yet the completion of the mission or proof of scientific success.
The milestoneThe milestone
BepiColombo entered its arrival phase after the Mercury Transfer Module separated from the spacecraft stack on 3 September 2026. ESA says ground stations confirmed the separation and telemetry indicated nominal systems. The event happened more than 200 million kilometres from Earth, where commands must be planned long before they are sent.
The mission is a joint ESA–JAXA project. Its science orbiters are ESA’s Mercury Planetary Orbiter, or MPO, and JAXA’s Mio. They are designed to study Mercury’s surface, interior, magnetic environment and surrounding plasma together, rather than treating the planet as only a photographed rock.
Why Mercury is hardWhy Mercury is hard
Mercury is close to the Sun, so a spacecraft must shed a great deal of orbital energy while managing heat and communications. BepiColombo used a long, carefully choreographed route through the inner Solar System instead of taking a simple direct path. The journey has lasted almost eight years and covered billions of kilometres.
What happens nextWhat happens next
ESA’s current timeline calls for the composite spacecraft to enter Mercury orbit on 21 November 2026. MPO will continue to power the stack until Mio separates on 9–10 December. The mission’s science phase is scheduled to begin in April 2027.
Those dates are plans, not completed results. The arrival sequence still depends on navigation, propulsion, communications and the health of both orbiters. The successful transfer-module separation is an important milestone, but it is not the same as science data arriving from a stable orbit.
| Stage | Status or planned date |
|---|---|
| Transfer module separation | Confirmed 3 September 2026 |
| Mercury orbit insertion | Planned for 21 November 2026 |
| Orbiter separation | Planned for 9–10 December 2026 |
| Science phase | Scheduled for April 2027 |
The headline is not “a probe reached Mercury”; it is that an eight-year mission has entered the high-stakes sequence that should place two orbiters around Mercury.
Primary sourcesEuropean Space Agency·Ars Technica