The Centre Spatial de Liège (CSL, ULiège) has started work on a project to extend its infrastructure and test capabilities, an investment of more than 26 million euros.
O
n 22 October, the CSL, which is celebrating its 60th anniversary, inaugurated the worksite during a joint visit by the Minister-President, Adrien Dolimont, Minister for Research, and the Vice-President of the Walloon Government, Pierre-Yves Jeholet, Minister for the Economy. Wallonia and the federal government, through Belspo (Federal Science Policy), are strongly supporting this major investment, which will enable the CSL to strengthen its position as a recognised centre of expertise in Europe for optical calibration of future "large" European Space Agency (ESA) missions.
1580 m2 additional
CSL will be constructing two new buildings on either side of its current facilities:
A new test tank: FOCAL-7
The new 7m diameter vacuum tank will be the largest at the CSL. FOCAL-7 (acronym for Facilité Optique de CAlibration à Liège, 7 for its diameter) will be nearly 14m long, including a hyper-stable optical bench 12m long and 4m wide, set on a seismic slab. The connection to a new nitrogen thermal system and cryogenic loops will enable optical calibrations of future space, scientific or Earth observation instruments to be carried out in the ultra-cold thermal environments required (approaching absolute zero).
A budget of €26.7 million
The Federal Science Policy (Belspo) is funding this investment to the tune of 12 million euros, covered by a contract with ESA. Wallonia is contributing 9.6 million euros, which will be entirely devoted to the acquisition of the FOCAL 7 vacuum tank, supplied by AMOS. ULiège is also contributing to the financial effort, through the CSL, to complete the total budget. The new facilities, which will double the surface area of the CSL's clean rooms and storage facilities, are due to come on stream in 2026.
Meeting the challenges of ESA's future 'large' missions
Future European Space Agency (ESA) missions will require increasingly large telescopes, often in hyper-cold environments, to improve the accuracy of measurements. The limitations of existing test facilities are a further constraint on the definition and design of a future scientific space mission. FOCAL-7 will make it possible to guarantee the best possible environmental conditions for these future missions, while giving experts greater freedom during the pre-design phases. In so doing, the CSL will consolidate its position on the European and global map of expertise in optical space calibration.
The Einstein telescope at CSL
ULiège is heavily involved in preparatory projects for the Einstein telescope (third-generation telescope for the detection of gravitational waves). Following the success of the E-TEST prototype, which will be tested at the CSL at the end of 2023, Wallonia is funding a laboratory dedicated to research activities linked to the Einstein telescope, as well as research projects to the tune of 3.75 million euros. This new laboratory, called Cristal (CRyogenic and Inertial STAbility Lab), will be located in the CSL's new buildings so as to benefit from the Centre's expertise in cryogenics and clean rooms. It will house an additional vacuum tank 3 metres in diameter, enabling the E-TEST prototype to be installed for further development.
Pierre-Yves Jeholet, Walloon Vice-President and Minister for the Economy: "The CSL, a key player in the Belgian space sector, is a tool of excellence for Wallonia. The aerospace sector is important for our region's economy because of its ability to create a large number of jobs: 2,000 direct employees and an annual turnover of 350 million euros! I'm delighted to see the extension of the Liège Space Centre, which will strengthen Wallonia's position as a world leader in the space sector. Walloon know-how is the pride of our region!
Adrien Dolimont, Walloon Minister-President: "The extension of the CSL marks an essential milestone for Wallonia in the space sector, a sector with high added value. This strategic investment of more than €26 million will strengthen our position as a key player in scientific innovation in Europe. The CSL, with its new state-of-the-art infrastructure, is set to play a crucial role in future European Space Agency missions. We are proud to support this project, which will enable Wallonia to remain at the forefront of technological advances and contribute to international research.
Founded in 1964 by the University of Liège, the Centre Spatial de Liège (CSL) is an applied research centre focused on the design of space observation instruments, with environmental test facilities serving the European Space Agency (ESA), the space industry and regional businesses. For almost 60 years, the CSL has been developing advanced technologies in optics, electronics, mechanics and thermics.
Among the CSL's remarkable facilities are its vacuum tanks (FOCAL: Facilité Optique de Calibration à Liège) of different diameters, which are installed in ultra-clean rooms to simulate the harsh space environment and test the operation of satellites and their instruments. The CSL also has the stimuli and optical calibration systems needed to validate the systems and instruments it designs or that are entrusted to it. The CSL is also developing expertise in coating and surface engineering technologies (micro-texturing, ion beam polishing, etc.).
CSL maintains an approved quality management system, based on the requirements of the European EN9100 and ESA (ECSS) systems, to ensure the highest quality of its services. Numerous scientific instruments for remarkable ESA and some NASA missions have been designed, built and tested at CSL. Others have also undergone space qualification in its clean rooms: EIT-SOHO, OM-XMM, FUV-SI-IMAGE, OMC-Integral, HI-STEREO, COROT, PACS-HERSCHEL, PLANCK, SWAP-Lyra-Proba-2, JUNO, GAIA, Tropomi, MIRI-JWST, EUI-HI- Solar Orbiter, CHEOPS, WISPR-Solar Probe Plus, FUV-ICON, MSI, Aeolus, Atlid, EUCLID, etc. and recently PROBA-3.
As a world-renowned centre of expertise, CSL collaborates with numerous European and international institutions (ESA, CNES, Thales Alenia Space, Belgospace, NASA, JAXA, ISRO, KARI, Airbus Defense and Space, FEDER, Wallonie, BELSPO, Wallonie Espace, etc.) and works on the continuous development of its performances in order to prepare for the evolutions of the space industry and to remain a key partner in space instrumentation and associated calibration as well as in the value chain of space data processing.
As a university research centre, the CSL enables students from the University of Liège, under the guidance of their teachers, to develop and build their scientific projects.
The CSL, located in the heart of the Parc Scientifique de Liège (LIÈGE science park), employs around one hundred highly qualified people.
The CSL is heavily involved in the next ESA mission, PROBA-3, scheduled for launch by an Indian launcher in a few weeks' time (29 November). PROBA-3 is a demonstration mission to fly two mini-satellites in formation, enabling an ASPIICS coronograph placed between the two satellites to study the solar corona. Belgium (via BELSPO) is making a significant contribution to the funding of this ESA mission, 3e of the PROBA series. CSL led the European consortium responsible for the design, development and manufacture of the ASPIICS instrument. All the sub-systems were supplied to the CSL, which carried out the integration, alignment and qualification tests of the instrument in a space environment.
Press release from the Council of Rectors dated February 4, 2026.
Découvrez comment nos chercheurs utilisent l'intelligence artificielle pour détecter des exoplanètes, prévoir la météo, protéger nos cultures ou encore assister les médecins.
This new report highlights not only the remarkable dynamism of the academic community, but also the significant progress made during the 2024-2025 academic year.
