But when the liquid helium tank is empty, the won't be dead in space. Instead, NASA engineers are getting ready to give it an entirely new life - its "warm mission".
"We like to think of Spitzer as being reborn," said Robert Wilson, Spitzer project manager at NASA's Jet Propulsion Laboratory, in a statement. "Spitzer led an amazing life, performing above and beyond its call of duty. Its primary mission might be over, but it will tackle new scientific pursuits, and more breakthroughs are sure to come."
Five and a half years in space, Spitzer is part of what NASA calls its Great Observatories -- a group of telescopes designed to see and capture images of the visible and invisible colors of the universe. The group includes the Chandra telescope and the , which will receive its last maintenance and upgrade next week by astronauts aboard the , which is slated to launch next week.
is probably best known for its aid in detecting exoplanets -- planets around other stars which are generally obscured from being seen from Earth. The telescope also has helped scientists discover that comets and planets are made up of the same material throughout the galaxy. It also has found hundreds of massive black holes billions of light-years away, according to NASA.
Ever since Spitzer was launched, liquid helium has run through it, chilling three of its instruments to -456 degrees Fahrenheit, which is less than 3 degrees above absolute zero -- the coldest temperature theoretically attainable. NASA engineers had projected that the cryogen would only last about two and a half years. Good design and efficient operations are being credited with extended the life of the coolant, according to NASA.
Now, when NASA says Spitzer soon will begin its warm mission, don't imagine that it'll be really warm. Maybe less frigid would have been more accurate.
Once the coolant runs out, Spitzer's temperature will only rise to -404 degrees Fahrenheit. As cold as that is, two of the telescope's instruments - the longer wavelength multiband imaging photometer and the infrared spectrograph - will no longer be cold enough to operate.
All is not lost, though. The telescope's shortest-wavelength detectors in its infrared array camera will continue to function. They are designed to detect the faint flow asteroids in our solar system, dusty stars, planet-forming disks, gas-giant planets and distant galaxies.
"We will do exciting and important science with these two infrared channels," said Spitzer Project Scientist Michael Werner, in a statement. "We're focusing on aspects of the cosmos that we still have much to learn about."