ESA and CAS Smile mission begins science operations in orbit

The European-Chinese Smile mission was declared ready to begin science operations on 23 September, the European Space Agency said, following a commissioning campaign that started after the spacecraft launched on 19 May and reached its science orbit on 20 June.

What changed

ESA said that on 23 September the mission was declared ready to start revealing how Earth responds to the wind of charged particles from the Sun, ending an in-space commissioning period that ran from 20 June.

According to ESA, European and Chinese teams spent that period deploying mechanisms, switching on units, checking all communications between the spacecraft and the ground, and fixing any issues that came up.

"Smile is now approved to begin science operations. This is a very important milestone – a true pleasure to announce – and I am sure our excellent collaboration will deliver ground-breaking data to scientists around the world," said Professor Carole Mundell, ESA Director of Science.

The four instruments

ESA said much of commissioning involved testing Smile's four science instruments: the soft X-ray imager (SXI), ultraviolet aurora imager (UVI), magnetometer (MAG) and light ion analyser (LIA).

The agency said the instruments will collect information to help better understand solar storms, geomagnetic storms and the science of space weather, including how solar activity interacts with Earth's magnetic field, leads to the auroras and can affect electronic infrastructure on and around Earth.

ESA released first footage from UVI, which it described as the first camera since 2008 to capture the full ring of northern lights around the North Pole in ultraviolet light. The agency said UVI is now recording the auroras for a record-breaking 45 hours at a time, and that the released footage was taken on 24 July 2026, two weeks after the instrument was switched on, showing activity in the auroral ring caused by a rush of solar wind particles disturbing Earth's magnetic field.

Stray light issue on the X-ray camera

ESA said SXI, a key European contribution to the mission, was successfully switched on and has taken its first images, including two test images of the aftermath of a distant exploded star.

However, the agency said that when the camera is pointed towards Earth it currently detects too much unwanted, or stray, light. Specific settings and software updates are being changed and implemented onboard, with ESA, the consortium of universities and companies behind the instrument, and the Chinese team leading spacecraft operations working together; ESA noted the instrument has a versatile design that can be adjusted remotely.

Because Smile is steadily pointing farther away from Earth and less light is emitted by the North Pole as northern winter approaches, the unwanted light is reducing naturally and is due to reach a minimum in mid-October, ESA said. At that point, according to the agency, SXI would take its first good image of the magnetopause or of the northern polar cusp.

Mission roles and documentary

Smile — the Solar wind Magnetosphere Ionosphere Link Explorer — is a joint mission between ESA and the Chinese Academy of Sciences (CAS). ESA said it provides the payload module carrying three of the four instruments, the SXI instrument, the launcher and assembly, integration and testing facilities, and contributes to UVI and to mission operations. CAS provides the other three instruments and the spacecraft platform and is overall responsible for operating the spacecraft in orbit.

ESA also released a documentary covering the mission's development between June 2024 and May 2026, described as the final instalment in the 'Let's Smile' series. The agency said Smile is part of its Cosmic Vision programme.

Read the original from ESA →