What is Skylab/ATM?

Skylab was launched from Cape Kennedy on May 14, 1973. On May 25th, it made history by becoming the United States' first full-scale manned space observatory. Altogether, three crews visited Skylab, operating its telescopes for 171 of the 251 days that the space station was operational. The third crew set a record by spending 84 days in zero gravity.

The purpose of Skylab was to study the sun, especially the corona with its flares and coronal transients (CME's). Skylab used several different telescopes mounted on its Apollo Telescope Mount (ATM) to look at the sun in X-Ray, ultraviolet, and H-alpha wavelengths, as well as white light. It was the best instrument of it's time, in terms of its resolution and wavelength coverage. It also had the distinct advantage of being located above the earth's atmosphere, where it could observe a greater wavelength band and not have to worry about clouds or atmospheric distortion.

The Apollo Telescope Mount (ATM) held the many solar telescopes on board Skylab. The ATM canister was as large as any solar observatory spar on Earth at the time, measuring 3 meters long and 2 meters in diameter. The primary advantage the ATM had over its predecessors was its use of photographic film. With the astronauts came the ability to load and unload film in ATM cameras and return the film to the surface of Earth. Nearly thirty film canisters were exposed and returned to Earth, providing scientists with over 150,000 exposures.

The astronauts on board the space station were quick to respond to the observations of ground-based scientists. When active prominences, flares, or mass ejections were detected, the observers in space would point their telescopes and record the event as well. Television displays were set up so that they could watch the sun in "real time," and make immediate decisions about the best way to observe.


Further information can be found in A New Sun: The Solar Results From Skylab by John A. Eddy (Publ. by National Aeronautics and Space Administration, Washington D.C., 1979).


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Author: Cathy Andrulis

Last revised January 31, 1996 - Cathy Andrulis