A joint scientific mission between the European Space Agency (ESA) and the Chinese Academy of Sciences (CAS), the Solar wind Magnetosphere Ionosphere Link Explorer (SMILE), launched successfully on May 18-19, 2026. The satellite lifted off aboard a Vega-C rocket from Europe's Spaceport in Kourou, French Guiana.
Launch Event and Orbit
The vehicle lifted off at 05:52 CEST on May 19 (11:52 p.m. EDT on May 18). This was the seventh Vega-C mission, designated flight VV29. The three-stage Vega-C successfully deployed SMILE into a circular orbit approximately 707 km (439 miles) above Earth, about 56 minutes after liftoff. The satellite's solar panels were subsequently deployed.
Mission Profile and Orbit Adjustments
Over the next 25 days, the satellite will perform 11 engine burns to reach its operational orbit. Source 3 reports more than 13 engine ignitions are required for the full orbital maneuver sequence. SMILE will enter a highly elliptical orbit, reaching approximately 121,000 km (75,185 miles) above the North Pole and 5,000 km (3,107 miles) above the South Pole.
Following orbital adjustments, mission teams will conduct checkouts of the spacecraft and its instruments. First X-ray and ultraviolet images are expected approximately three months after launch. The planned mission lifetime is three years.
Scientific Instruments and Objectives
SMILE carries four science instruments designed to study the interaction between the solar wind and Earth's magnetosphere. The mission aims to improve understanding of solar storms, geomagnetic storms, and space weather, which can affect infrastructure such as power grids, GPS, and satellites.
The instruments include:
- Soft X-ray Imager (SXI): Provided by ESA, this instrument uses lobster-eye optics to produce wide-field images of the boundary (magnetopause) where the solar wind meets the magnetosphere via solar wind charge exchange.
- Ultraviolet Imager (UVI): Co-developed by CAS and ESA. Canada initially participated in UVI development but withdrew; China subsequently took the lead, with ESA providing image intensifiers and coated mirrors.
- Light Ion Analyser (LIA): Provided by CAS, China's National Space Science Center (NSSC).
- Magnetometer (MAG): Provided by CAS, fully developed by NSSC.
Institutional Responsibilities
- Chinese Academy of Sciences (CAS): Responsible for the satellite platform (including power, propulsion, attitude control, and command), spacecraft operations, and three of the four science instruments (UVI, LIA, MAG). The Innovation Academy for Microsatellites of CAS led the satellite system design and platform development.
- European Space Agency (ESA): Provided the payload module, the Soft X-ray Imager, assembly and testing integration services, the Vega-C launch vehicle, and contributed to the UVI instrument. ESA will assist with operations, including an integrated data link between tracking stations.
- Operations: After launch, teams from China and Europe will jointly conduct flight control operations.
Vega-C Rocket Details
The Vega-C is a 35-meter (115-foot) tall, 210-tonne rocket developed through ESA and built by Italian prime contractor Avio. The rocket uses three solid-propellant stages and a liquid-propellant fourth stage. Vega-C debuted in July 2022. This was its seventh flight, with six previous successful missions. The rocket experienced a failure on its second flight in December 2022, which grounded the vehicle before its return to flight.
This mission was the first Vega-C flight operated by Avio; prior missions were managed by Arianespace. This transition follows a period of reduced European access to space after the retirement of the Ariane 5 and the temporary grounding of Vega-C.
Context and Significance
The mission launches during the declining phase of Solar Cycle 25, which reached solar maximum around October 2024.
SMILE represents a mission-level, full-scale cooperation between CAS and ESA. It was approved in 2015. The mission is based on fundamental science with open data policies. It is one of the most visible joint missions between the two agencies, conceived before recent strains in EU-China research relations.
Previous China-Europe space science collaborations include the Dark Matter Particle Explorer, TianGuan satellites, and Sino-French astronomy satellites. Both sides plan to explore future cooperation models, including the proposed CATCH microsatellite constellation project.