Photo credit: NASA/JPL-Caltech
NASA’s Spitzer Space Telescope (SST), formerly the Space Infrared Telescope Facility (SIRTF), is basically an infrared space telescope launched in 2003 and still operating as of 2019. This large celestial mosaic of the Cepheus C and Cepheus B regions taken by the SST includes multiple clusters of stars born from the same dense clumps of gas and dust, with some older than others and more evolved, making it a generational stellar portrait. This two-instrument image was compiled using data gathered from the Infrared Array Camera (IRAC) and the Multiband Imaging Photometer (MIPS) during Spitzer’s “cold” mission, before the spacecraft’s liquid helium coolant ran out in 2009. Read more for another video about the SST and additional information.
The initial planned mission period was around 2.5 years with a pre-launch expectation that the mission could extend to five or slightly more years until the onboard liquid helium supply was exhausted on May 15, 2009. Without liquid helium to cool the telescope to the extremely low temperatures needed to operate, most of the instruments are no longer usable. However, the two shortest-wavelength modules of the IRAC camera are still operable with the same sensitivity as before the cryogen was exhausted, and have continued to be used to the present in the Spitzer Warm Mission. All of the Spitzer data, from both the primary and warm phases, are archived at the Infrared Science Archive (IRSA).