Spitzer Space Telescope Begins 'Beyond' Phase
Celebrating the spacecraft's ability to push the boundaries of space science and technology, NASA's Spitzer Space Telescope team has dubbed the next phase of its journey "Beyond."
"Spitzer is operating well beyond the limits that were set for it at the beginning of the mission," said Michael Werner, the project scientist for Spitzer at NASA's Jet Propulsion Laboratory in Pasadena, California. "We never envisioned operating 13 years after launch, and scientists are making discoveries in areas of science we never imagined exploring with the spacecraft."
NASA recently granted the spacecraft a two-and-a-half-year mission extension. This Beyond phase of the Spitzer mission will explore a wide range of topics in astronomy and cosmology, as well as planetary bodies in and out of our solar system.
Understanding the early universe is one of many areas where Spitzer has broken ground. Spitzer's Infrared Array Camera (IRAC) was designed to detect remote galaxies roughly 12 billion light-years away -- so distant that their light has been traveling for roughly 88 percent of the history of the universe. But now, thanks to collaborations between Spitzer and NASA's Hubble Space Telescope, scientists can peer even further into the past. The farthest galaxy ever seen, GN-z11, was characterized in a 2016 study using data from these telescopes. GN-z11 is about 13.4 billion light-years away, meaning its light has been traveling since 400 million years after the big bang.
"When we designed the IRAC instrument, we didn't know those more distant galaxies existed," said Giovanni Fazio, principal investigator of IRAC, based at the Harvard Smithsonian Center for Astrophysics (CfA). "The combination of the Hubble Space Telescope and Spitzer has been fantastic, with the telescopes working together to determine their distance, stellar mass and age."
Spitzer reinvented itself in May 2009 with its warm mission, after the depletion of the liquid helium coolant that was chilling its instruments since August 2003. At the conclusion of the "cold mission," Spitzer's Infrared Spectrograph and Multiband Imaging Photometer stopped working, but two of the four cameras in IRAC persisted. Since then, the spacecraft has made numerous discoveries despite operating in warmer conditions (which, at about minus 405 Fahrenheit or 30 Kelvin, is still cold by Earthly standards).
"With the IRAC team and the Spitzer Science Center team working together, we've really learned how to operate the IRAC instrument better than we thought we could," Fazio said. "The telescope is also very stable and in an excellent orbit for observing a large part of the sky."
Spitzer's Beyond mission phase will last until the commissioning phase of NASA's James Webb Space Telescope, currently planned to launch in October 2018. Spitzer is set to identify targets that Webb can later observe more intensely.