A 102cm Balloon-Borne Telescope For Far-Infrared Astronomical Observations

In early 1971, the Harvard Smithsonian Center for Astrophysics and the University of Arizona engaged in a cooperative program to develop a balloon-borne gryo-stabilized, 102-cm telescope capable of carrying out far-infrared observations of astronomical interest above the earth's atmosphere. Since 1972 the telescope has been flown and successfully recovered a total of sixteen times. Ten of the flights have provided high quality astronomical data resulting in more than eighty hours of photometric and spectroscopic observations of numerous astronomical objects. The telescope and its modes of operation are described, including the attitude control systems and the methods of aspect determination. A brief summary will be given of the in-frared instrumentation used. The experience gained from the operation of balloon-borne infrared telescopes and from development of new infrared instrumentation has been extremely valuable when applied to space experiments, particularly the infrared telescopes planned for operation on the Space Shuttle.