The X-Ray Universe

Abstract

Scarcely a year after the end of WWII, the distinguished American astronomer Lyman Spitzer wrote up a classified report which recommended the design and construction of large space-based telescopes to cut through the turbulence of the Earth’s atmosphere in order to provide the most detailed images of the universe ever produced. Indeed, he went on to approve the construction of giant telescopes up to 600 inches at a time when the 200-inch Hale reflector was still on the drawing board. Like so many great ideas, Spitzer’s far-reaching vision went largely unnoticed until the advent of the Space Race a decade later. Lloyd Berkner, the then-chairman of the Space Science Board of the National Academy of Sciences, solicited more suggestions for space based astronomy projects. Initially, the response from the astronomical community was to design a number of small space telescopes capable of imaging objects at UV wavelengths. Called the Orbiting Astronomical Observatory (OAO) satellites, these consisted of a series of four American space observatories launched by NASA (with collaborations with the British Science and Research Council) during the years 1966 through 1972, and which provided the first high-quality observations of many objects at wavelengths shorter than the human eye could see. Although two of OAO missions ended in complete failure, the success of the other two greatly increased awareness within the astronomical community of the tremendous benefits of space-based observations. Indeed, it was these proof-of-concept spacecraft would eventually lead to the development of the Hubble Space Telescope (HST).