The PRIMA (Probe far-IR Mission for Astrophysics) mission selected by NASA for a phase A study

The PRIMA (Probe far-IR Mission for Astrophysics) mission selected by NASA for a phase A study

NASA has just selected the PRIMA project (The PRObe for Infrared Mission for Astrophysics) for a phase A study, from among around ten proposals. This study phase, which will last one year, will enable the project to be evaluated in depth before a final decision is made. If PRIMA is selected, NASA will allocate a budget of one billion dollars for its development, with a launch scheduled for 2031.

PRIMA is a telescope designed to observe the far infrared, which will provide answers about the origin and evolution of planets, supermassive black holes, stars and cosmic dust.

France is playing a major role in this mission, thanks in particular to the participation of CNES, the Laboratoire d’Astrophysique de Marseille (LAM) and CEA, which are collaborating on the development of one of the project’s key instruments, the PRIMAger imager. On a European level, the project also benefits from the support of SRON (Netherlands) as well as institutes in Italy and the United Kingdom (Cardiff), reinforcing the international dimension of the team.

Design of the PRIMA telescope Credits: NASA-JPL-Caltech
Description of the PRIMA mission

The PRIMA project is an innovative space observatory with a 1.8-metre telescope designed to study far-infrared wavelengths. It bridges the gap between existing infrared observatories, such as NASA’s James Webb Space Telescope (JWST), and ground-based radio telescopes.

The project is based on two major scientific instruments:

  • FIRESS (Far InfraRed Spectrometer System), an ultra-sensitive spectrometer covering a range from 25 to 80 microns, capable of low-resolution spectroscopy (R~200) for broad observations and medium-resolution (R~5000) for more detailed studies. Developed by the Jet Propulsion Laboratory (JPL) in Pasadena, this instrument will enable cosmic phenomena to be observed with great precision.
  • PRIMAger, a multi-band spectrophotometric imager/polarimeter optimised for wavelengths between 25 and 300 microns. It will offer two bands: the first, hyperspectral (25-80 microns, R~10), and the second, including polarimetric capabilities (80-300 microns). This development is the fruit of an international collaboration between the LAM, the CEA (Paris-Saclay and Grenoble sites) and the SRON (Netherlands).

Operating in the far infrared, PRIMA’s success is based on advanced cryogenic technologies (operating temperature at 4.5 K), enabling exceptionally sensitive observations.

Description of the PRIMA mission Credits: NASA-JPL-Caltech
PRIMA mission objectives

PRIMA’s scientific objectives are vast and include:

  • The co-evolution of galaxies and supermassive black holes through infrared observation of the dynamic processes that link them.
  • The study of the formation of the first heavy elements and dust grains in the early universe, providing crucial information on the chemical evolution of the universe.
  • The analysis of proto-planetary disks, making it possible to determine chemical abundances and to compare these data with the atmospheres of exoplanets, in order to better understand the role of water and other compounds in the formation of planets.
  • The study of small bodies in the Solar System, in particular objects in the Kuiper Belt, for which PRIMA will be able to observe sizes between 35 and 80 km, inaccessible to previous missions such as Spitzer or Herschel.
  • A complete hyperspectral survey of the sky, thanks to PRIMAger. If this survey is carried out successfully during the open observation time, planned for a period of one year (out of PRIMA’s five-year lifetime), it will constitute an unprecedented database, providing essential information for the world astronomical community.
The scientific objectives of the PRIMA mission Credits: NASA-JPL-Caltech
Next stages in the project

The next key step for the PRIMA team will be the final selection of the project by NASA, scheduled for 2026. If PRIMA is selected, the PRIMAger instrument, in which France is participating, will be delivered to the Jet Propulsion Laboratory (JPL) by the end of 2029. The launch of the mission is scheduled for March 2031.

CEA Paris-Saclay Contact: Marc SAUVAGE

CEA Grenoble Contact: Ivan CHARLES & Thomas PROUVE

Further information: Project website