NASA picks PRIMA far-infrared telescope for new Probe Explorer class

NASA announced on 1 October 2026 that PRIMA — the PRobe far-Infrared Mission for Astrophysics — had advanced into Phase B development, becoming the first mission selected under its new Probe Explorers class within the long-running Explorers Program. Designed around a 1.8-metre cryogenically cooled far-infrared telescope, PRIMA will survey wavelengths that current observatories like the James Webb Space Telescope cannot reach, chasing the obscured history of how galaxies and their supermassive black holes grew, how planets form in dust-shrouded disks beyond our Solar System, and how dust and heavy elements first built up in the early universe. The move into Phase B unlocks further preliminary design work and formal technical and budget reviews ahead of a planned 2033 launch. International partners contributing hardware and science include ESA members through CNES, ASI, DLR and the UK Space Agency, as well as CSA, KASI and JAXA. NASA framed Probe Explorers as a cost-capped mid-size mission line sitting between its smaller Explorer missions and the agency's flagship observatories, intended to produce flagship-class discoveries on tighter schedules and budgets.