This hatch was part of the unmanned Apollo 6 Command Module (CM 020), which was launched in April 1968, to evaluate the Saturn V Apollo system. The Apollo hatch had to provide an adequate seal for proper cabin pressurization, thermal protection during re-entry, and water-tight conditions during splashdown and recovery. An example of the "unified hatch" designed following the fatal Apollo 204 fire in January 1967, the Apollo 6 hatch covered the side opening in both the pressurized cabin and the external heat shield that covered the spacecraft.
The hatch was transferred from NASA Johnson Space Center to the Smithsonian Institution in 1974.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.