Which astronomer first proposed a large space telescope in 1946?

Lyman Spitzer first proposed a large space telescope in 1946. In his report “Astronomical Advantages of an Extra-Terrestrial Observatory,” he described how a telescope above Earth’s atmosphere could transform astronomy.

Spitzer identified two major benefits: space telescopes would avoid atmospheric turbulence that blurs ground-based images, and they could observe wavelengths such as ultraviolet and infrared light that Earth’s atmosphere blocks or absorbs. His proposal was remarkable because it came more than a decade before Sputnik, the first artificial satellite.

The idea took decades to become practical. In 1965, the National Academy of Sciences created a committee to define the scientific goals of a large space telescope, with Spitzer as its chair. NASA’s Large Space Telescope program eventually developed into Hubble, launched in 1990.

Edwin Hubble gave the telescope its name, but he was not the person who originated the space-telescope concept. Spitzer’s pioneering advocacy earned him the nickname “father of Hubble”; NASA later also named the Spitzer Space Telescope in his honor.