The Prima mission has multiple objectives:

➡️ to better understand the formation of planets and their atmospheres, particularly the transport of water in protoplanetary disks

➡️ to study the coevolution of galaxies and their supermassive black holes

➡️ to trace the evolution of dust and heavy elements in the interstellar medium during galaxy formation​

Prima will carry two instruments, including the PRIMAger imager led by CNES with contributions from CNRS and CEA. Recognized for its expertise in cryogenics, the CEA will contribute to the instrument's thermal architecture, provide the flight model of the thermal link—which connects the detectors to the satellite's cryogenic system—and develop ground-based cryogenic test facilities. These facilities will enable the characterization of the PRIMAger instrument prior to its delivery to NASA.

This work builds on previous efforts by the teams at CEA-Irig/DSBT/LCCS​ and CEA-Irfu, who had already contributed to the cryogenic components of the Herschel telescope, notably a cooling system operating at 300 millikelvins, or -272.85°C—less than one degree from absolute zero! For Prima, the efforts go even further, with a thermal link operating at just 100 millikelvin.

Cryogenics is essential for high-quality infrared measurements. This radiation is, in fact, linked to emitted heat. However, space instruments and telescopes emit their own heat as they operate. Because these systems are ultra-sensitive, they risk being “blinded" by this emitted heat instead of detecting the desired radiation from the far reaches of the universe!