SPACE: With PRIMA, NASA will try to build a billion-dollar space telescope in record time.

PRIMA, which has a cost cap of $1.2 billion excluding launch costs, will not be as big and complex as Roman, so it’s natural to assume a shorter development cycle. NASA wants to launch PRIMA seven years from now, in 2033. The telescope will observe the Universe in faint, far-infrared light in a range of wavelengths between 24 and 235 micrometers, requiring its primary optics to be cooled to 4.5 Kelvin, or minus 451° Fahrenheit.

This would usually require a brand-new build of a sophisticated cryocooler. PRIMA will instead use a spare leftover from the development of the James Webb Space Telescope, modified to use helium-3 instead of helium-4 as the cooling fluid. The focal planes of PRIMA’s kinetic inductance detectors will be chilled even lower to 100 milliKelvin, putting the mission’s optics in contention for the coldest ever sent into space.

Nifty.