NASA Will Shut Down the Spitzer Space Telescope Thursday

NASA’s Spitzer Space Telescope has been an essential tool in understanding the cosmos for the last 16 years, but it’s about to take its final bow. Spitzer still works, but the cost of operating it is getting too high to justify the scientific return. NASA will shut down the observatory on Jan. 30, paving the way for new projects like the long-delayed James Webb Space Telescope.

Spitzer launched in 2003 aboard a Delta 2 rocket, eventually taking up a position 160 million miles (260 million kilometers) from Earth in orbit of the sun. This is one of NASA’s “Great Observatories” along with Hubble, the Chandra X-ray Observatory, and the Compton Gamma Ray Observatory. You probably haven’t heard much about that last one because Compton suffered a hardware failure and was deorbited 20 years ago. Chandra and Hubble are still operational, so Spitzer will be the first Great Observatory to go dark because of budgetary concerns.

NASA made the decision to end Spitzer’s mission after reviewing a 2016 report that ranked six major astrophysics missions by the value of the data. Spitzer ended up at the bottom, so NASA announced its intention to shut down the mission in 2019. The telescope has been gathering data right up until the end, and scientists will still be making discoveries with that data for years to come.

NASA plans to retrieve the last of Spitzer’s observations today (Jan. 29) before shutting the instrument down on Thursday. The team will transmit a command to the telescope instructing it to go into safe mode. It will go into a “sun coning” attitude and remain there indefinitely.

NASA spent $11 million on Spitzer in 2018, which is down from the $17 million it spent in 2014. The telescope is still useful, too. It has a 33.5-inch primary mirror that focuses light on an array of infrared detectors. Over the years, NASA has used Spitzer to spot a previously unknown ring of Saturn, study some of the earliest stars in the universe, and even detect exoplanets. In fact, Spitzer discovered five of the seven known planets in the TRAPPIST-1 solar system.

The nail in Spitzer’s coffin is the impending launch of the James Webb Space Telescope, which also has advanced infrared imaging capabilities. The Webb telescope’s mirror is 50 times larger than Spitzer’s, allowing it to observe much fainter objects. Getting this instrument launched has been a challenge, to say the least. After years of delays and budget overruns, NASA hopes to deploy the James Webb Space Telescope in early 2021. It has already spent about $10 billion building the telescope, much more than the $1.36 billion total cost of the Spitzer mission. Hopefully, it proves to be a worthwhile investment.