Spitzer lasted far longer than planned. When the spacecraft launched, it had a prime mission of only two and a half years. The spacecraft exhausted its supply of helium coolant in 2009, ending some infrared observations, but it was able to continue work at some shorter infrared wavelengths.
The end of Spitzer leaves NASA without a space-based infrared telescope at least until the launch of JWST, followed by the Wide-Field Infrared Survey Telescope in the mid-2020s. However, Hertz said on NASA TV he was not worried about any gap in infrared observations. “We’re well-positioned to continue studying the universe in infrared, and the gap of a year or so really is not a concern.”
