-
Galileo
used two lenses in a long tube to view objects ten times further away. -
Isaac Newton
built the first reflecting telescope -
William Herschel
built a large reflecting telescope with a four-foot diameter mirror -
Oberth and Spitzer
Hermann Oberth proposed the idea of a space-based telescope
in 1920 which was expanded by Lyman Spitzer. -
Copernicus
The first space telescope was launched
