Apollo Command Module (Block II) Master Events Sequencer Controller (MESC), measuring 12 x 13 x 9, labeled on one side, “Controller—Sequence Master Events, AIIA, 65675-107-161.” Additional part numbers are stenciled to the left, “06362AAJ8413” and “V36-540040-9.” Inspection labels affixed to another side are headed, “Acceptance Thermal Testing Time” and “Acceptance Vibration Time.” In fine condition, with chipping to white paint. The MESC was a component of the spacecraft's Sequential Events Control System (SECS) subsystem, which regulated automatically sequenced functions during mission ascent, entry, flight, and in the event of an abort. The MESC governed activities including Launch Escape Tower jettison, Service Launch Adapter separation, Command Module/Service Module separation and Earth Landing System deployment. It also directed Launch Escape System actuation and Service Propulsion System abort modes. As the Master Controller for the SECS, MECS interfaced with and commanded the following controllers: Emergency Detection System, SM Jettison Controller, Lunar Module Separation Sequence Controller, Command Module Reaction Control System Controller, Earth Landing Sequence Controller, and the Translation Controller. A desirable, mission-critical piece of hardware.
Terms and abbreviations used in our descriptions.