Key facts
- NASA announced on September 23, 2026, that PRIMA is advancing to Phase B; the note was updated on September 24 to reflect current international partners.
- PRIMA will be the first mission of the Probe Explorers class, within NASA's Explorers Program.
- Its 5.9-foot telescope will conduct deep and sensitive surveys in the far-infrared.
- The mission will address the origins of exoplanets, the evolution of galaxies and black holes, and the accumulation of dust and heavy elements.
- The launch targets 2033, and the planned duration is five years.
- Before starting Phase C implementation, PRIMA must pass a technical, programmatic, and cost review. If confirmed, the project cost will be capped at $1.2 billion, excluding launch and other non-project costs.
- JPL will manage the mission, with participation from Goddard and Marshall centers and contributions from international partners.
Related records
NASA announced on September 23, 2026, that PRIMA will advance to Phase B of development, the stage where preliminary design and mission technology are developed. PRIMA stands for Probe far-Infrared Mission for Astrophysics and will be the first mission of the Probe Explorers class, integrated into NASA's Explorers Program. The press release was updated on September 24 to reflect current international partners.
What PRIMA will observe
With a 5.9-foot diameter telescope, PRIMA will conduct deep and sensitive surveys of the universe in far-infrared light. NASA explains that the mission will help bridge the gap between existing infrared observatories—such as the James Webb Space Telescope—and radio telescopes.
By studying radiant energy that only emerges in the far-infrared, PRIMA will address questions about the universe. These include the origins of planets outside the solar system; how galaxies and their black holes have grown and evolved throughout cosmic history; and how dust and heavy elements have accumulated over time. NASA notes that these investigations will contribute to a better understanding of why the universe looks the way it does today.
A new class within the Explorers Program
Probe Explorers is a new class of astrophysics missions within the Explorers Program, which NASA describes as its oldest ongoing program. It is designed to provide frequent and low-cost access to space through investigations led by principal investigators. Since the launch of Explorer 1 in 1958, the program has launched more than 100 missions.
The 2020 Decadal Survey of the National Academies of Sciences, Engineering, and Medicine, Pathways to Discovery in Astronomy and Astrophysics for the 2020s, recommended that NASA establish the Probe Explorers class. The agency selected PRIMA for development after evaluating Probe Explorer mission concept studies based on their scientific merit, the feasibility of their development plans in cost and schedule, and the use of technologies that could support future large missions.
Schedule, cost, and pending review
NASA aims to launch the observatory in 2033 and plans a five-year mission. Before beginning Phase C implementation, PRIMA must pass a confirmation review based on its technical, programmatic, and cost performance. If confirmed, the project cost will have a limit of $1.2 billion, excluding launch and other non-project costs.
NASA's Jet Propulsion Laboratory, JPL, will manage PRIMA. The Goddard Space Flight Center and the Marshall Space Flight Center are also participating. The mission will feature contributions from CNES, ASI, DLR, the Canadian Space Agency (CSA), KASI/KASA, JAXA, and the UK Space Agency.
Sources: NASA announcement on PRIMA and background on the Probe Explorers class.