Apollo Telescope Mount

Mission Profile

Apollo Telescope Mount (ATM) was a solar observatory originally conceived as a standalone spacecraft to be flown aboard an Apollo Applications Program mission before being redesigned as the primary science instrument cluster of Skylab. Mounted on a truss structure at one end of the Skylab station, the ATM carried eight solar telescopes and coronagraphs observing in wavelengths from X-ray through visible light, operated by crews who performed EVAs to change film canisters in the instruments. During Skylab's three crewed missions in 1973-1974, the ATM accumulated over 150,000 solar images and roughly 200 km of magnetic tape data, capturing unprecedented observations of solar flares, coronal holes, and the dynamic solar corona in a way no automated satellite of that era could achieve.