When a camera has spent nearly eight years crossing the inner Solar System, the first picture does not need to be pretty. It just needs to prove the thing still works. BepiColombo’s SIMBIO-SYS instrument has now done exactly that.
The Italian Space Agency announced on October 6 that the instrument activated all three of its optical channels in their final flight configuration on September 15, 2026. It captured several stars as bright points and returned telemetry showing that the system is operating correctly.
That is the useful headline. The picture was not a glamorous close-up of Mercury. It was a systems check, taken before the spacecraft enters orbit. For a camera suite that has been folded into a complex spacecraft stack since its October 2018 launch, a boring image is very good news.
First light is a health check, not the science show
SIMBIO-SYS stands for Spectrometers and Imagers for MPO BepiColombo Integrated Observatory System. It rides on ESA’s Mercury Planetary Orbiter, usually shortened to MPO. The instrument’s job is to photograph Mercury, map its shape and examine what its surface is made of.
The September test confirmed that its acquisition systems survived the long cruise. Teams will now fine-tune operating conditions before routine science begins. Think of this as switching on every burner after moving a complicated stove across a continent. Dinner is not ready, but the kitchen works.
One instrument, three ways to read a planet
SIMBIO-SYS is really a coordinated set of three optical channels, and each sees a different part of the story.
- Stereo Imaging Channel: photographs Mercury from two viewing angles to build the first global three-dimensional map of the planet. The Italian Space Agency says its images can reach about 60 metres per pixel.
- High Resolution Imaging Channel: targets smaller features at about 6 metres per pixel, useful for examining craters, faults, volcanic landforms and other geological details.
- Visible and Near-Infrared Hyperspectral Imager: splits reflected light into wavelengths that can help scientists identify minerals and connect composition with terrain.
The clever part is not any one camera. It is the combination. Shape, fine detail and composition can be studied together instead of as three unrelated datasets.
The rest of the toolbox woke up too
ESA says every instrument on MPO was switched on together on September 15 for the first time since the Mercury Transfer Module separated on September 3. The early analyses found the instruments in good health.
The BELA laser altimeter fired its laser in space for the first time, sending more than 700,000 pulses over 21.5 hours. It will eventually use reflected pulses to measure Mercury’s topography. MERTIS, a thermal infrared instrument, collected roughly one gigabit of data during a 22-hour performance test. ESA reported little to no loss in the spectrometer’s sensitivity compared with its 2013 low-temperature ground calibration.
Why Mercury deserves this much trouble
Mercury is the smallest rocky planet and the closest one to the Sun. It is also the only planet besides Earth with a global magnetic field. Yet it remains the least explored planet in the inner Solar System.
There are wonderfully stubborn questions waiting there. Why does a scorched planet keep water ice inside permanently shadowed polar craters? What produced its oversized iron core and magnetic field? What carved the shallow, bright depressions called hollows?
BepiColombo is built as a two-orbiter answer. ESA’s MPO will concentrate on the surface, interior and composition. JAXA’s Mio spacecraft will study the magnetic field, magnetosphere and surrounding plasma. Watching the same world from complementary orbits should help connect what happens on the ground with what happens in the charged environment above it.
The dates to circle next
BepiColombo has not entered Mercury orbit yet. ESA’s current arrival timeline lists these milestones:
- November 21, 2026: MPO and Mio, still stacked together, are scheduled to be captured into a polar orbit around Mercury.
- December 9 to 10, 2026: MPO is scheduled to release Mio into its final elliptical polar orbit.
- December 16, 2026: MPO is scheduled to release Mio’s sunshield and continue lowering its own orbit.
- March 10, 2027: MPO is scheduled to reach its final orbit.
- April 6, 2027: the mission’s routine science phase is scheduled to begin.
ESA notes that exact dates can change for operational reasons. Spacecraft operations near the Sun are not a place for stubborn calendars.
For now, the first-light image is a modest victory. A few points of starlight have confirmed that a camera launched in 2018 can still open its eyes. The spectacular pictures can wait until Mercury fills the frame.
Sources
- ESA arrival updates, October 6, 2026: instrument health, BELA and MERTIS test results, and current arrival status.
- Italian Space Agency first-light report, October 6, 2026: SIMBIO-SYS test date, channel functions, resolution figures and team details.
- ESA arrival timeline, updated July 2026: scheduled orbital milestones and operational caveat.
- JAXA BepiColombo mission overview: Mio’s role and the division of work between the two orbiters.
Image credits
Featured Image: observatory under a starry sky by Jason D / Pexels. Inline images: red-lit observatory telescope by Earth Photart / Pexels and desert observatory by Chris Munnik / Pexels. All are illustrative photographs used under the Pexels License, checked October 8, 2026.
