Collection Item Summary:
Mercury spacecraft 12 was originally delivered to Cape Canaveral as a backup for the MA-8 capsule (Sigma 7 flown by Walter Schirra). However, the capsule was returned to McDonnell and reconfigured for an extended 1-day Mercury mission. This reconfigured capsule, labeled 12B, was never assigned to a flight and thus was never re-delivered to the Cape or flown.
In 1967 NASA transferred Mercury 12B to the Smithsonian Institution.