Launched in orbit around the sun in 2003, Spitzer relieved some of the oldest galaxies in the universe, unveiled a new ring around Saturn and looked out through dust banks to study newborn stars and black holes.
It helped with the discovery of planets outside our solar system, including the detection of seven planets in full size around orbit around the star TRAPPIST-1, in addition to other achievements.
"In his 15 years of operations, Spitzer has opened our eyes to new ways to view the universe," said Paul Hertz, director of the Astrophysics Division at NASA headquarters in the US.
"Spitzer's discoveries range from our own planetary backyard, to planets around other stars, to the far reaches of the universe." By collaborating with Nasa's other Great Observatories, Spitzer has helped scientists get a fuller picture of many cosmic phenomena, "he said.
With its infrared vision and high sensitivity, Spitzer has contributed to the study of some of the most distant galaxies in the known universe.
The light of some of those galaxies traveled 13.4 billion years to reach the earth. As a result, scientists see these galaxies as they were less than 400 million years after the birth of the universe.
In recent years, scientists have used Spitzer to study exoplanets or planets in orbit other stars than our sun, although this was not expected by the telescope's designers.
Spitzer also played a key role in one of the most important exoplanet discoveries in history: the detection of seven, about planets of terrestrial planets in orbit around a single star.
The TRAPPIST-1 planetary system was different from any alien solar system that was ever discovered, with three of its seven planets in the & # 39; habitable zone & # 39 ;, where the temperature might be good for the existence of liquid water at the surfaces of the planets.
Their discovery was a tempting step in the search for life elsewhere in the universe.
"The study of extrasolar planets was still in its infancy when Spitzer was launched, but in recent years more than half of Spitzer's observation time has often been used for research into exoplanets or searches for exoplanets," says Lisa Storrie-Lombardi, project manager from Spitzer at JPL.
"Spitzer is very good at characterizing exoplanets even though it was not designed to do that," Storrie-Lombardi said.
Spitzer has registered 106,000 hours of observation time. Thousands of scientists around the world have used Spitzer data in their studies and Spitzer data are cited in more than 8,000 published articles.
Spitzer's primary mission ended 5,5 years, during which time the spacecraft worked in a "cold phase" with a supply of liquid helium that cooled three instruments on board to just above absolute zero.
The cooling system reduced excess heat from the instruments themselves that could pollute their observations. This gave Spitzer a very high sensitivity to "cold" objects.
In July 2009, after Spitzer's helium stock was exhausted, the spacecraft entered a so-called "warm phase."
The main tool of Spitzer, the infrared array camera (IRAC), has four cameras, of which two remain in the warm phase with the same sensitivity that they have retained during the cold phase.