SAFIR

SAFIR (or Single Aperture Far-InfraRed) is a proposed NASA space observatory for far-infrared light. The plan calls for a single large mirror 5–10 meters (16–33 ft) in diameter, cryogenically cooled to 5 kelvins (−268 °C; −451 °F). This would feed detector arrays sensitive from 5 to 1000 µm. The possibility of servicing such a telescope in space has been evaluated.

The design for SAFIR's primary mirror is large for a space-based telescope; for comparison, SAFIR's predecessor, the 2003 Spitzer Space Telescope, has a primary mirror only 0.85 meters (2.8 ft) in diameter. SAFIR is oriented towards longer wavelengths so the mirror does not have to be as accurate compared to visible and near-infrared telescopes like the Hubble Space Telescope.