This is a highly detailed 1:6 scale model of Stratoscope II, a balloon-borne 36-inch reflecting telescope mounted in a 3.5-ton stabilized gondola that flew in the 1960s. The model includes four optical components: the primary mirror (a 6-inch mirror 1-inch thick, aluminized, as well as a Gregorian secondary mirror on a three-vane spider mount and a flat tertiary diagonal mirror that sends the light into the spectrograph sitting at right angle to the telescope. There is a smaller mirror in the spectrograph housing as well, a Cassegrain-type hole in its center to represent the way the light eventually reached the film cannister).
Stratoscope II was a follow-on project to Stratoscope I, a 12-inch balloon-born telescope conceived by Princeton astrophysicist Martin Schwarzschild and flown several times in the late 1950s to photograph the sun. Stratoscope II flew about six times from 1963 to 1971, lofted by a Mylar balloon with a volume of over 5 million cubic feet. The instrument was designed to work in the photographic infrared, to study the molecular composition of planetary atmospheres, the atmospheres of red giant stars and to make high-resolution images of the nuclei of bright galaxies.
This model was exhibited at the Seattle World's Fair in 1962. The Perkin-Elmer Corporation donated the scale model to the collection in 1964.