NASA is progressing with the development of the Probe far-Infrared Mission for Astrophysics (PRIMA), a new space telescope designed to observe the infrared universe more deeply than the James Webb Space Telescope (JWST). According to a recent agency statement, the mission has entered Phase B, the preliminary design and technology development stage. If the upcoming management review is successful, PRIMA is scheduled to launch no earlier than 2033 for a five-year operational mission.
Equipped with a 1.8-meter (5.9-foot) telescope, PRIMA will target far-infrared wavelengths, distinct from the near- and mid-infrared spectrum primarily observed by JWST, which launched in 2021. While other instruments like Hubble and the Nancy Grace Roman Space Telescope detect some infrared light, PRIMA’s specific focus is on unraveling the origins of exoplanets, the growth of galaxies, and the evolution of black holes.
Meredith MacGregor, an associate professor of physics and astronomy at Johns Hopkins University, highlighted the mission’s unique capabilities. She noted that current instruments cannot address key questions regarding planet formation, such as quantifying water’s role or determining gas masses and elemental abundances in planetary disks. “We can’t actually address these science questions with JWST,” MacGregor explained, “because the spectral lines that are required are only in the far-infrared.”
The University of Maryland and Caltech, both instrumental in the mission’s development, expressed enthusiasm for the project. Alberto Bolatto, an observational astronomer at UMD and PRIMA co-investigator, stated he is “elated to be part of the future of astronomy” and look forward to producing a tool that significantly advances scientific knowledge. Lee Armus, a staff scientist at Caltech and the mission’s science operations lead, added that he is particularly eager to investigate how powerful molecular outflows influence star formation and supermassive black hole growth over cosmic time.
PRIMA operates under a project cost cap of $1.2 billion, excluding launch and other non-project expenses. This stands in contrast to JWST, which cost approximately $10 billion at launch. The mission marks the inaugural entry in NASA’s new “Probe Explorer” class, a category intended to bridge the gap between flagship missions like JWST and smaller agency efforts. These probes are part of the longstanding Explorers Program, which began with the 1958 launch of Explorer 1 and has since supported over 100 missions.
The Probe Explorer concept was recommended by astrophysicists in the 2020 Decadal Survey. In 2024, NASA funded $5 million each for two concepts: PRIMA and the Advanced X-ray Imaging Satellite. After a detailed evaluation based on scientific merit, feasibility, and technological utility, NASA announced on September 23 that PRIMA was selected for development.
If the mission proceeds as planned, NASA’s Jet Propulsion Laboratory will manage PRIMA, with contributions from various NASA centers and international partners.
A ‘Probe Explorer’ class seems like a great middle ground. We need more mid-tier missions rather than just giant flagships.
What exactly does PRIMA see that JWST misses? The article mentions spectral lines, but a quick comparison would help laypeople understand.
I just hope the 2033 launch date isn’t delayed again like JWST. Five years of silence during preliminary design scares me.
$1.2 billion is surprisingly cheap for a flagship-class mission. Smart budgeting by NASA, but will they cut corners elsewhere?
Finally, a telescope focused on far-infrared! Water content in exoplanet atmospheres has been a missing puzzle piece for years.