CNES and JAXA sign SOLAR-C Implementing Arrangement

3 February 2025, CNES Chairman & CEO Lionel Suchet and Hitoshi Kuninaka, Director General of the
Institute of Space and Astronautical Science (ISAS) at the Japan Aerospace Exploration Agency (JAXA),
signed an Implementing Arrangement under the Framework Agreement governing the two agencies’
partnership on the SOLAR-C high-sensitivity ultraviolet solar spectroscopy satellite.
An international collaboration led by Japan involving several European nations and the United States,

SOLAR-C is set to launch at the end of 2028. The mission aims to gain new insights into the fundamental physical mechanisms driving solar plasma dynamics and understand how the Sun transfers its energy to the rest of the solar system through phenomena like solar flares or the solar wind, which eject huge quantities of particles from its atmosphere in the form of plasma.

ISAS and the National Astronomical Observatory of Japan (NAOJ) are developing the satellite and its instrument, a first-of-its-kind high-performance ultraviolet telescope designed to observe the Sun and its atmosphere.

This Extreme UltraViolet high-throughput Spectroscopic Telescope (EUVST) hopes to pierce the secrets of how high-temperature solar plasma is formed and better understand the Sun’s impacts on Earth and the solar system. With its primary mirror and highly sophisticated EUV Grating Assembly (EGA), EUVST’s very compact optics are expected to offer a level of performance far superior to more traditional systems.

CNES is funding the design, development and fabrication of the EGA. It is supporting research teams at the IAS space astrophysics institute and the Charles Fabry laboratory, both attached to the national scientific research centre CNRS, which are working on development of the EGA, and has responsibility for delivery of this vital element for EUVST’s spectroscopic functions.

After the signing ceremony, CNES Chairman & CEO Lionel Suchet commented: “Long-standing Space cooperation between France and Japan has proved most fruitful in recent years.

It is now continuing with SOLAR-C following on from the Hayabusa 2-MASCOT and MMX missions. SOLAR-C is a new mission with high technological and scientific stakes that promises to map the Sun as never before with unprecedented resolution. CNES is proud to be involved thanks to its world-renowned expertise.” Source: CNES