Lot #8098
Apollo Command Module Simulator Sextant/Telescope Optical Components

Optical components of the CM simulator's sextant and scanning telescope
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Estimate: $15000+


Optical components of the CM simulator's sextant and scanning telescope

Two optical components from the sextant (SXT) and scanning telescope (SCT) of an Apollo Command Module simulator, famously called the 'Great Train Wreck' by John Young. The large optical assembly is for the scanning telescope (SCT), measuring approximately 38″ x 16″ x 9″, and comprises a long optical tube terminating in a lens marked "L200-100-208 ASS'Y"; on the other end is the interior faceplate that has indicators for shaft angle and trunnion measurements. The dials and partial electronics for these two windows remain intact behind the faceplate. The two round hex recess-head parts on the face plate that look like screws are actually emergency backup drive units. A space tool inserted in the hex recess could be used to unlock and then drive the shaft and trunnion of the SCT manually. The scanning telescope served as a 'finder' for stars and was a unity power (1X) instrument. The SCT was coupled electronically to the sextant and stars located in the center of the image in the SCT would be in, or near, the center of the field of view in the sextant. An angled eyepiece would have been attached to the front of the plate for looking through the Scanning Telescope.

The smaller assembly, measuring approximately 18″ x 9″ x 9″, forms the second half of the sextant/telescope viewing panel; the sextant (SXT), and would also have had an eyepiece attached. In the flight sextant the angle information was provided to the Apollo Guidance Computer electronically. The piece terminates in an optical tube that in the simulator, as for the SCT, would have attached to optics for viewing a large star simulator globe. The sextant is a 28-power instrument. In overall very good condition.

From NASA's publication Apollo Expeditions to the Moon (SP-350), discussing the Command Module simulator: ''The great train wreck' was John Young's description of the contraption beyond the console. At the top of the stairs was a compartment that exactly duplicated a command module control area, with all switches and equipment. Astronauts spent countless hours lying on their backs in the CM simulator in Houston. Panel lights came on and off, gauges registered consumables, and navigational data were displayed. Movie screens replaced the spacecraft windows and reflected whatever the computer was thinking as a result of the combined input from the console outside and astronaut responses. Here the astronauts practiced spacecraft rendezvous, star alignment, and stabilizing a tumbling spacecraft. The thousands of hours of training in this collection of curiously angled cubicles paid off. Many of the problems that showed up in flight had already been considered and it was then merely a matter of keying in the proper responses.'

Auction Info

  • Auction Title: Space & Aviation
  • Dates: #581 - Ended April 16, 2020