If you are a longtime follower of astronomy news, you find yourself learning a lot of weird acronyms. When I was young, I was excited by four letter-jumbles in particular: LST, GRO, AXAF, and SIRTF, the abbreviated names for NASA's four Great Observatories. They would be launched into space to view the universe without the handicap of having to look through our planet's distorting atmosphere, with each observatory taking a unique perspective. LST would look at visible light, GRO at gamma rays, AXAF at x-rays, and SIRTF at infrared radiation, like light but with a longer wavelength.
All four of them eventually turned into real missions with real names. LST (the Large Space Telescope) became the Hubble Space Telescope. GRO (the Gamma Ray Observatory) became Compton. AXAF (the Advanced X-ray Astrophysics Facility) became Chandra. SIRTF—pronounced "SIR-tiff," the Space Infrared Telescope Facility—was the last one to be launched, in 2003, and now it is the latest of the four to come to the end of its life. NASA put it to eternal sleep on January 30, 2020, after 16 triumphant years of discovery.
SIRTF is better known by its final name, the Spitzer Space Telescope, in honor of Lyman Spitzer, Jr. What's in a name? In this case, a lot. Spitzer, the man, was a great visionary of 20th century astronomy. He was one of the first scientists to recognize that our galaxy is a dynamic place, pulsing with hot gas and still forming new stars. He was a pioneer in nuclear fusion research, founding the Princeton Plasma Physics Lab—still one of the world's leading fusion-energy research centers. Most relevant here, he also was the inspiration behind both the Hubble and the Spitzer Space Telescopes.
