Orbiting Astronomical Observatory 2
The Orbiting Astronomical Observatory 2 was the first successful space telescope, launched on December 7, 1968. An Atlas-Centaur rocket launched it into a nearly circular altitude Earth orbit. Data was collected in ultraviolet on many sources including comets, planets, and galaxies. It had two major instrument sets facing in opposite directions; the Smithsonian Astrophysical Observatory and the Wisconsin Experiment Package. One discovery was large halos of hydrogen gas around comets, and it also observed Nova Serpentis, which was a nova discovered in 1970.
Celescope: Smithsonian Astrophysical Observatory
The Smithsonian Astrophysical Observatory, also called Celescope, had four 12 inch Schwarzschild telescopes that fed into Uvicons. The Uvicon was an ultra-violet light detector based on the Westinghouse Vidicon. Ultraviolet light was converted into electrons which were in turn converted to a voltage as those electrons hit the detection area of the tube. There has been a Uvicon in the collection of the Smithsonian Institution since 1973.Various filters, photocathodes, and electronics aided in collecting data in several ultraviolet light passbands. The detectors showed a gradual loss of sensitivity and the experiment was turned off in April 1970. By the time it finished about 10 percent of the sky was observed resulting in a catalog of 5,068 UV stars.
Wisconsin Experiment Package
The Wisconsin Experiment Package had seven different telescopes for ultraviolet observations. For example, there was a nebular photoelectric photometer fed by a 16-inch telescope with a six-position filter wheel that unfortunately failed a few weeks after launch.Construction was supervised by Arthur Code of the University of Wisconsin-Madison. WEP observed over 1200 targets in ultraviolet light before the mission ended in early 1973.