Country of Origin: United States of America
3-D Test: 1.9 x 8.9cm (3/4 x 3 1/2 in.)
The Apollo spacecraft used a sextant for navigation between the Earth and Moon. Operation of the sextant involved sighting through a telescope; this filter was placed over one of the sextant's two scopes.
This object was flown on Apollo 9, and was transferred by NASA to the Smithsonian in 1975.
Transferred from the National Aeronautics and Space Administration