NASA selected PRIMA for Phase B on September 23, 2026, advancing the proposed far-infrared space telescope through preliminary design and technology development. Before the mission can enter Phase C implementation, it must pass a confirmation review, NASA said.
NASA selects PRIMA for Phase B
Phase B is the stage for advancing a mission’s preliminary design and developing its technology. NASA’s decision moved PRIMA forward in that process; implementation is a possible next step after a confirmation review.
NASA’s Jet Propulsion Laboratory manages PRIMA, with NASA’s Goddard and Marshall centers as partners.
The far-infrared observations PRIMA is designed for
PRIMA is designed to observe far-infrared light, extending coverage beyond the shorter infrared wavelengths mainly studied by the James Webb Space Telescope and toward the longer wavelengths studied by radio observatories. That reach is intended to help investigate planet-forming material and water, as well as the evolution of galaxies and black holes.
The mission’s listed design includes a 1.8-meter, all-aluminum telescope designed to operate at 4.5 K. Its kinetic inductance detector (KID) arrays are specified to operate at 100 millikelvin, with approximately 12,000 detectors in total. The planned orbit is around the Sun–Earth L2 point, and the listed instantaneous field of regard is 26% of the sky, according to the PRIMA Observatory specifications.
What PRIMAger and FIRESS are designed to measure
PRIMA’s two instruments have different observing modes and wavelength ranges. A micrometer (μm) is one-millionth of a meter.
| Instrument | Mode | Wavelength range | Resolving power |
| PRIMAger | Hyperspectral imaging | 25–80 μm | R = 8 |
| PRIMAger | Imaging and polarimetry | 91–261 μm | R = 4 |
| FIRESS | Spectroscopy | 24–235 μm | R > 85 |
The science questions NASA lists for PRIMA
NASA says PRIMA is intended to study how planets form and the role of water, how galaxies and black holes evolve, and the history of cosmic dust and heavy elements. Together, those goals use far-infrared observations to examine both planet-forming environments and changes across the universe over time.
NASA’s launch target and project cost cap
NASA’s September 23, 2026 announcement set 2033 as PRIMA’s launch target and described a planned five-year mission, conditional on the project passing confirmation. NASA also set a $1.2 billion project cost cap if PRIMA passes that review; the cap excludes launch and other non-project costs.
