Apollo Telescope Mount

• 1. Origins And Development

  ›

  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.

  124

• 2. 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.

  5710

• 3. Operational Mechanics

  ›

  Astronauts manually operated the Apollo Telescope Mount during missions in 1973 and 1974. Data came principally as exposed photographic film returned to Earth with the crew. Film canisters required manual retrieval by astronauts during spacewalks. The heaviest canisters weighed 40 kilograms or 88.1 pounds. Each could hold up to 16,000 frames of film. Over the course of operations almost 30 canisters were loaded and utilized before return. Some instruments provided a live video feed observable from inside the station. Astronaut Paul J. Weitz sat at the telescope's command and display console during the June 1973 mission. This console allowed direct control over the observational systems. First Polaroid photos taken in space captured a Skylab CRT video screen displaying the Sun. These instant film-to-hard copy images recorded data from an ATM instrument. The film magazines remained among the heaviest items that had to be returned at the end of each mission. Crew members performed these complex tasks while managing power systems for both the observatory and the station itself.

  910

• 4. Mission History And Data Recovery

  ›

  The Apollo Telescope Mount conducted observations throughout 1973 and 1974. Over 150,000 successful exposures were recorded on film during these missions. Six experiments used film to capture solar data across various wavelengths. Astronauts retrieved full film canisters during spacewalks to exchange them with empty ones. Returned film was transported back to Earth aboard the Apollo capsules when each mission ended. As of 2006, original exposures remained accessible to interested parties at the Naval Research Laboratory in Washington, D.C. Thermal vacuum testing subjected the ATM to rigorous conditions before launch. Engineers monitored temperature stability and system integrity under simulated space environments. The windmill-like arrays on the ATM fed power to both the observatory and the station. These arrays remained undamaged due to protection within the launch shroud. They provided enough power for crewed operations until the one remaining workshop array could be deployed. This deployment occurred during the first crewed mission to Skylab. The success of this operation allowed continued scientific work despite initial damage to the main station.

  4510

• 5. Scientific Findings And Experiments

  ›

  Instruments observed the Sun using pre-planned experiments and student participation. A chart described an example of this work labeled ED 24. The S-54 X-Ray Spectrographic Telescope captured detailed spectral data from solar flares. Hydrogen Alpha telescopes tracked specific emissions from the solar atmosphere. Ultraviolet spectroheliographs mapped surface features invisible to visible light cameras. Student experiments contributed to the broader dataset collected by the eight major instruments. Results included observations across soft X-ray, ultraviolet, and visible light wavelengths. Data helped scientists understand dynamic processes occurring on the Sun's surface. The combination of film records and live video feeds offered unique perspectives. Researchers analyzed exposures to identify patterns in solar activity cycles. The Naval Research Laboratory preserved these findings for future study. Access to original exposures allowed new generations of astronomers to verify conclusions. The student component brought educational value alongside technical achievement. These efforts demonstrated how a complex observatory could support diverse research goals simultaneously.

  71012

• 6. Legacy And Preservation

  ›

  A backup ATM spare unit was restored and put on display in 2015. The Steven F. Udvar-Hazy Center in Chantilly, Virginia, US hosts the exhibit today. Restoration involved repairing some Kapton layers that had degraded after four decades. Instruments were mounted to this spare unit before it became inactive. The restoration process ensured public access to historical space technology. Original data remains archived at the Naval Research Laboratory in Washington, D.C. Interested parties can still request access to exposures taken during 1973 and 1974 missions. The Apollo Telescope Mount stands as a testament to engineering ingenuity from the early 1970s. Its design influenced later solar observatories including Orbiting Solar Observatory projects. Lists of X-ray space telescopes include this system among pioneering instruments. Spacewalks conducted during Skylab missions remain part of historical records from the period. The University of Alabama in Huntsville Archives and Special Collections holds additional documentation. External links provide further resources for researchers studying this era of space exploration. The legacy continues through preserved hardware and accessible scientific archives.

  13