Infrared space telescope Spitzer is one of NASA’s four Great Observatories and today, January 30, 2020, it will transmit its final science and engineering data to mission control. After more than 16 years in orbit, studying everything from nearby planets to some of the most distant known galaxies, Spitzer will be officially decommissioned.
The Great Observatories program is a series of space observatories – Hubble, Chandra, Compton Gamma Ray, and Spitzer – designed for astronomical study using different wavelengths: visible, gamma rays, X-rays, and infrared.
Spitzer has no direct successor but the James Webb Space Telescope (JWST), which should launch in the next few years, will act as a hybrid offspring for both Spitzer and Hubble. The many delays that have plagued JWST led the Spitzer mission to be extended for a fifth and final time in 2018, but now, unfortunately, it's showing its age. Just like your phone, once it could transmit data continuously, but now it takes just 2.5 hours to drain its battery completely, so the decision was made to retire it. It's legacy, however, lives on.
"Spitzer taught us how important infrared light is to understanding our universe, both in our own cosmic neighborhood and as far away as the most distant galaxies," Paul Hertz, director of astrophysics at NASA Headquarters, said in a statement. "The advances we make across many areas in astrophysics in the future will be because of Spitzer's extraordinary legacy."
The telescope was launched into space on August 25, 2003, where it was to operate for 2.5 years. Infrared telescopes are equipped with coolant to keep them at dramatically low temperatures so they can study the heat signatures from celestial bodies. The team hoped that they could double the program duration and Spitzer exceeded those expectations. It ran out of coolant 5 years, 8 months, and 19 days after it launched.
While it was limited without coolant, the mission team was still able to perform incredible science with this marvelous instrument. In its 6,000 days of service, Spitzer produced the largest and most detailed infrared portrait of the Milky Way by taking over 800,000 snapshots of it. Spitzer also discovered the largest ring of Saturn.
One of its greatest achievements is also one of the most significant discoveries of the last few years: the exoplanets surrounding the TRAPPIST-1 star. of the seven exoplanets, five of these were discovered with Spitzer data alone and the other two were confirmed by it. Spitzer was also used to study the atmospheres of these distant worlds.
Spitzer is the second of the Great Observatories to be decommissioned. The Compton Gamma Ray Observatory launched in 1991 and deorbited in 2000. The other two, however, are still going strong. The Chandra X-ray Observatory is in its third decade of operation, and the Hubble Space Telescope will have its 30th birthday in orbit on April 24 this year.