The Solar Wind Magnetosphere Ionosphere Link Explorer (Smile) is a joint mission between the European Space Agency (ESA) and the Chinese Academy of Sciences (CAS). Using X-ray and UV cameras, as well as particle and magnetic field detectors, Smile will give humankind its first complete look at how Earth reacts to streams of particles and bursts of radiation from the Sun.

The latest milestone confirms that Smile has successfully completed its ten-month Assembly, Integration and Testing (AIT) phase, which lasted from November 2024 to September 2025 at ESA’s technical centre, ESTEC, in the Netherlands.

The mission is now ready for the launch preparation activities, with launch scheduled during the period 8 April to 7 May 2026, on a Vega-C rocket from Europe’s Spaceport in French Guiana. With many launches planned from Europe’s Spaceport next year, the logistics of launch campaigns require careful planning and launch windows. The launch day within the month-long window will be defined early next year.

“I’m very proud that the collaboration between our Chinese colleagues and our ESA teams has gone so well and that we’re on the right track to launch in spring 2026,” says ESA Director of Science Prof. Carole Mundell. “Building on the 24-year legacy of our Cluster mission, which ended science operations last year, Smile is the next big step in revealing how our planet’s magnetic shield protects us from the solar wind.”