Flown power amplifier for the Sequential Events Control System (SECS) from the Apollo 15 Command Module Endeavour, measuring 5″ x 3″ x 1.75″, marked on the top plate: "Amplifier, Power Supply, Signal, NAA/S&ID Cont No. ME473-0083-0012, Stock No., Contract No. NAS 9-150, Manufacturing Date 10-67, Electro Development Corp, Seattle, Washington, Mfr Ser No. 20, Mfr Part No. 2-611-12." The unit bears a label identifying various inputs and outputs, and has numerous quality control stamps and stickers. Includes the North American Rockwell temporary parts removal tag, reading, "Part Number ME473-0083-0012, Serial/Lot Number 20, Authority TPS 146 Ashur 112564, REM #1027," with the "Identity of Next Assembly" section reading, "Amplifier P/S, Part Number V36-000002-161, Serial Number S/C 112, Mark for Shipment of: R.F.T. S/C 112, Inspector 2/28/73." The "S/C 112" notation signifies Apollo CSM-112, which was given the call sign Endeavour. In fine condition.
The Sequential Events Control System (SECS) was the Apollo spacecraft subsystem that controlled the automatically sequenced functions during the mission and any aborts. It also provided conditioned signals to telemetry equipment so that vital information could be downlisted to the Manned Space Flight Network, which could then be used by ground personnel in determining the status of the mission. As a piece of an important system flown into lunar orbit on Apollo 15, this is a decidedly rare and desirable piece of space hardware.
Terms and abbreviations used in our descriptions.