The Apollo Telescope Mount [or ATM, named because of its association with the Apollo Applications Program] was this country’s first full-scale, manned astronomical observatory in space. Many unmanned astronomical spacecraft had preceded it, including the highly sophisticated and successful Explorer, Mariner, Pioneer, Orbiting Astronomical Observatory, and Orbiting Solar Observatory (OSO) spacecraft. The manned Mercury, Gemini, and Apollo missions carried astronomical apparatus, which was employed with good results by astronauts, but none of these instruments approached the size and overall capability of the battery of solar telescopes that made up the ATM. [Note: another OSO spacecraft was launched post-Skylab, in 1975; it remained operational through late 1978.]According to A New Sun, the “smiley-faced” ATM consisted not just of one, but eight separate solar experiments, operating with X-ray, ultraviolet, and hydrogen-alpha capabilities (in addition, there was also a white light coronagraph, which provided high-resolution views of the Sun’s corona).
To give the reader a sense of how big this thing was, A New Sun provided a comparison/contrast between the OSO spacecraft and Skylab:
The largest solar instruments on the pre-Skylab OSOs were about one meter long, weighed less than 25 kg [55 lbs], and worked with power budgets of a few watts… Total spacecraft weight was about 275 kg [606 lbs], of which was about half was allotted to solar instruments. Skylab, by comparison, was bigger than a boxcar and weighed over 90,000 kg [almost 200,000 lbs]. The ATM experiment canister, which housed the eight principal solar telescopes, was three meters long and over two meters in diameter – as large as any modern solar observatory spar on Earth, and it was pointed at the Sun with an accuracy and steadiness that equaled the performance of an observatory telescope on the ground.The ATM even had its own power source – its four unmissable solar power vanes, and A New Sun mentioned the full-sized solar instruments “had virtually no power restrictions.”
|From NASA: "Graphical representation of an ultraviolet photograph depicting a solar flare." From the Skylab 4 mission, 1974.|
Want to know more? Check out the Skylab panel at Spacefest VII, moderated by me, on the evening of Friday, June 10, 2016. Hear about America's iconic space station from those who were there!