SMILE mission cleared for science operations as X-ray imaging work continues

The European Space Agency said its joint SMILE mission with the Chinese Academy of Sciences was declared ready for science operations on 23 September 2026. The spacecraft is designed to study how particles from the Sun interact with Earth’s magnetic environment, a process tied to auroras and space weather. Its ultraviolet imager has recorded auroral activity, but work continues on the X-ray camera needed for the mission’s planned images of Earth’s magnetic boundary.

The declaration followed months of checks in space. ESA says SMILE launched on 19 May and reached its target orbit for science operations on 20 June. Since then, European and Chinese teams have deployed mechanisms, switched on equipment, checked communications and addressed issues that arose during commissioning. Approval to begin operations marks a change in the mission’s status; ESA has not presented it as the completion of SMILE’s main scientific objectives.

What SMILE’s four instruments are designed to measure

SMILE carries a soft X-ray imager, an ultraviolet aurora imager, a magnetometer and a light ion analyser. The mission’s planned approach combines images of large-scale activity with measurements of particles and magnetic fields at the spacecraft. Researchers aim to examine the connection between incoming solar-wind activity, changes around Earth’s magnetic field and the auroras visible near the poles.

A peer-reviewed overview of the mission describes the intended combination more specifically: soft X-ray images of the magnetopause and polar cusps, ultraviolet images of the auroras, and measurements of plasma and magnetic fields. The magnetopause is the boundary where the solar wind meets Earth’s magnetic field. The northern polar cusp is a region where charged particles can be channelled toward Earth. These are targets for observation, not results established by the readiness announcement.

ESA says this work should improve understanding of solar and geomagnetic storms and the science of space weather. Such disturbances can affect electronic infrastructure on and around Earth. The agency’s account describes what the mission is built to investigate; it does not report a new forecast capability or a finding about any particular storm.

What the ultraviolet camera has already recorded

ESA has released footage from SMILE’s ultraviolet aurora imager taken on 24 July, about two weeks after the instrument was switched on. The agency describes activity in the ring of northern lights following a disturbance in Earth’s magnetic field caused by an influx of solar-wind particles. That footage shows one instrument operating and recording an event. It is distinct from the X-ray images of Earth’s magnetic boundary that the mission is also intended to produce.

According to ESA, the ultraviolet instrument can record the northern aurora for as long as 45 hours at a time. Sustained views of the auroral ring are one part of SMILE’s planned combined observations: the mission overview describes simultaneous auroral imaging alongside X-ray imaging and measurements made at the spacecraft. The present footage demonstrates ultraviolet observation, while the full planned combination still depends on further work with the X-ray imager.

Why the X-ray images of Earth are still pending

The soft X-ray imager has been switched on and has taken test pictures of distant supernova remnants, ESA says. Those pictures were checks of the camera, not views of Earth’s magnetopause or polar cusp. When the instrument points toward Earth, it currently detects too much unwanted stray light. ESA says teams are changing settings and implementing software updates aboard the spacecraft to reduce that light.

The instrument’s development has involved specialist detector work. The Open University’s Centre for Electronic Imaging describes its contribution to the X-ray camera’s CCD detectors, including work on performance, radiation effects, calibration and modelling of instrument background. That account, last updated in April 2021, provides technical context for the camera; it is not a report on the current stray-light problem or the mission’s operational status.

ESA also expects the stray light to diminish naturally as SMILE points farther away from Earth and the North Pole emits less light toward northern winter. The agency expects the unwanted light to reach a minimum in mid-October, when it says the camera could take its first good image of the magnetopause or northern polar cusp. That timing remains an expectation: ESA has not said such an image has been obtained, quantified the present stray-light level or guaranteed when the planned observation will succeed.

SMILE is a joint mission of ESA and the Chinese Academy of Sciences. ESA says it supplied the payload module, the soft X-ray imager, the launcher and assembly and testing services, and contributes to the ultraviolet imager and operations. The Chinese academy provided the other three science instruments and the spacecraft platform, and is responsible overall for operating the spacecraft in orbit. Its next reported milestone will depend on whether the X-ray adjustments yield usable images of the regions the mission was built to study.