An Apollo Command/Service Module Block II Thrust Vector Position Servo Amplifier (TVSA) manufactured by Honeywell, 5.75″ x 12.5″ x 6″, 12.5 pounds, the top featuring four ‘J’ ports with ITT Cannon part stamps, and the bottom end bearing an affixed parts tag: “Servo Amplifier, Thrust Vector Position, Mfr. Part No. BG288G5, Sock No. ME901-0708-0302, Contract No. M7J7XAH-470005A, Mfr. 100288AG1018, Mfr. Date 3 Oct 1968.” In fine condition, with scattered scuffs and wear.
The TVSA was part of the Apollo CSM Block II’s Stabilization and Control Systems, a backup system to the PGNCS (primary guidance, navigation, and control system) that can sense and control spacecraft attitude and velocity changes during flight. The SCS is located in the command module and consists of a reaction jet and propulsion solenoids driver assembly, electronics control assembly, electronics display assembly, gyro display coupler, thrust vector position servo amplifier, two gyro assemblies, and various displays and controls. The SCS can hold the spacecraft to a local vertical attitude during earth or lunar orbit by using orbital rates, or to a specific attitude by using reference gyros mounted in the spacecraft. Information about spacecraft attitude and rate of attitude change is displayed to the astronaut. Steering and thrust signals can be sent to operate the reaction control and service propulsion systems.
From The Peter Gerry Collection.
