— Ch. 1 · Origins And Development —
Apollo Telescope Mount.
~5 min read · Ch. 1 of 6
The Apollo Telescope Mount began as a concept within the late 1960s Apollo Applications Program. Engineers studied ways to use infrastructure from the Apollo lunar missions for new purposes in the 1970s. Early plans involved mounting instruments on a deployable unit attached to the Service Module of an Apollo spacecraft. Later, designers shifted to using a modified Lunar Module to house controls and recording systems. The descent stage of that module was replaced with a large solar telescope and solar panels. This configuration allowed three crew members to operate the equipment before returning to Earth. As other concepts were dropped, only the space station and this observatory remained active projects. Plans then changed to launch the ATM and have it connect to Skylab in orbit. Both spacecraft would be operated by crews aboard the station. When later Apollo landing missions were cancelled, a Saturn V rocket became available for this purpose. The wet workshop concept was no longer needed. Instead, engineers launched an expanded dry version of the station. The ATM was now attached directly to the station during launch. A Saturn V rocket had enough power to lift both at once. This change saved the program when a problem destroyed one workshop solar panel during launch. The windmill-like arrays on the ATM provided power until the remaining workshop array could be deployed.
Design And Instrumentation
NASA's Marshall Space Flight Center managed the design and construction of the Apollo Telescope Mount. Engineers actively cooled the system to keep instrument temperatures within specific ranges. Pointing the observatory relied on the Skylab computer, which astronauts commanded from inside the station or via Earth links. Four external solar panels deployed into an X shape after launch. These panels provided around 30% of the station's total electrical power. Eight major observational instruments sat on the mount alongside several lesser experiments. Together they observed light wavelengths ranging from 2 to 7000 angstroms. This range covered soft X-rays, ultraviolet light, and visible light. Two X-ray telescopes carried designations S-054 and S-056. An X-ray and extreme ultraviolet camera bore the code S-020. Three ultraviolet instruments included the spectroheliograph S-082A, the spectroheliometer S-082B, and the spectrograph S-055. Two Hydrogen Alpha telescopes operated as H-alpha no. 1 and H-alpha no. 2. A coronagraph held the designation S-052. Experiment S149 attached to one of the ATM solar panels added another layer of observation capability.