This is the Maurer earth/sky observer camera from an unpiloted test flight of the Mercury Atlas rocket and spacecraft in 1961. Without a pilot and hand-held camera to take photographs out the two small porthole windows of the spacecraft, NASA relied on this camera, positioned to point out the lower window, to capture images of Earth automatically.
This camera was transferred from NASA to the Museum in 1978.
This object is on display in James S. McDonnell Space Hangar at the Steven F. Udvar-Hazy Center in Chantilly, VA.