This black metal cylinder, housing a Cassegrain 10-inch mirror system and a 5 inch oval mirror tilted at 45 degrees is mounted on the bottom of the secondary mirror. This assembly comprises the target acquisition optics from the backup Skylab infrared spectrometer used in Earth resources evaluation experiment. This experiment was designed to evaluate the usefulness of data from a spectrometer to the study of earth resources. The instrument was pointed and tracked manually by an astronaut at the lowest point of the Skylab's orbit using a telescope. This mirror-based optical system was manufactured by the Martin Marietta Aerospace Group for NASA.
It was transferred to NASM from NASA's Johnson Space Flight Center in 1979.
Transferred from the National Aeronautics and Space Administration