The T-21 spacecraft is a full-scale model of the Surveyor spacecraft built by Hughes Aircraft Company under the management of NASA's Jet Propulsion Laboratory. The spacecraft was used as an engineering thermal control model for testing. The Jet Propulsion Laboratory refurbished the T-21 in 1968 to look like the Surveyor 7 spacecraft that was sent to the Moon. The T-21 is missing the solid retrorocket, which was located in the center of the craft. The retrorocket was used to slow the decent of the Surveyor spacecraft that landed on the lunar surface.
Transferred by NASA's Jet Propulsion Laboratory. Hughes Aircraft Company is the manufacturer of the Surveyor spacecraft under the management of the Jet Propulsion Laboratory. Refurbished by JPL 1968 to look like Surveyor 7.