NASA’s PRIMA mission, the first in a new class of space telescopes, is on track to launch in the early 2030s. The Probe far-Infrared Mission for Astrophysics will be the first of NASA’s Probe Explorers, a new line of observatories designed to do more science for less money. With a cost cap of $1.2 billion excluding launch costs, PRIMA aims to balance the smaller Explorer missions and multibillion-dollar flagships like the Roman Space Telescope.

PRIMA will observe the universe in far-infrared light, requiring its primary optics to be cooled to 4.5 Kelvin. Instead of building a new cryocooler, PRIMA will use a spare leftover from the James Webb Space Telescope, modified to use helium-3. Its focal planes will be chilled to 100 milli Kelvin, potentially making it the coldest ever sent into space.

The mission will study the origins of planets and their atmospheres, the coevolution of galaxies and black holes, and changes in dust and metals over cosmic time. PRIMA will set up shop at the Sun-Earth L2 Lagrange point, a million miles from Earth, and peer deeper into infrared bands than any previous NASA observatory.

NASA announced PRIMA as the sole finalist after disqualifying the X-ray observatory AXIS earlier this year. PRIMA will be led by NASA’s Jet Propulsion Laboratory in Pasadena, California. The agency aims to launch PRIMA seven years from now, in 2033, which would be a record time for a mission of this scale.