Early astronauts sustained high "G forces" from acceleration during launch, and deceleration during reentry because they were launched on modified ICBMs and reentered on steep trajectories. In order to make these forces more tolerable, the astronauts had special form-fitting couches during Project Mercury, the first U.S. human spaceflight program. The two-person Gemini spacecraft had ejection seats, which made a full form-fitting couch infeasible. Instead, Gemini astronauts had two pieces made specially for them, the countour backboard, and the "pelvic block" in which they sat.
This contour backboard was made for Virgil I. "Gus" Grissom, who was the commander on the first Gemini mission with astronauts, Gemini 3, on March 23, 1965. This backboard did not fly on Gemini 3 but was probably used for training. McDonnell-Douglas Corporation gave it to the Smithsonian in about 1971 on behalf of NASA.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.