by Michael Werner, Project Scientist, Spitzer Space Telescope—Jet Propulsion Laboratory, California Institute of Technology

NASA’s Spitzer Space Telescope, launched in August 2003 and decommissioned in January 2020 after more than 16 glorious years of exploration of the universe at infrared wavelengths, was a technical and scientific marvel. Infrared astronomical studies at wavelengths longward of 1 micron, somewhat beyond the limit of human vision at around 0.7 microns, began in earnest around 1960. These early studies, carried out on ambient temperature telescopes within the atmosphere, advanced astronomical understanding of targets from planets within the solar system to distant and highly luminous galaxies. However, they could not disguise the fact that the earth is a hostile environment for infrared astronomy.