Flown Apollo Command Module Block I Earth Landing Sequence Controller flown on the Apollo 4 mission, measuring 7 x 4.5 x 3, bearing a large parts tag affixed to the top, reading: “Item Name: Sequence Controller, NAA Control No. ME 901-0001-001, Contract No. NAS 9-150, NAA Inspection Serial No. 06398AAF0227, Manufacturer: Northrop Ventura, Mfr Serial No. 43, Mfr Part No. R6920-517.” One side is stamped twice in black text, “S/C 017, Post Recov Item.” The unit has four connector ports labeled “J1” through “J4,” and a blue “Static Air” port. Scattered marks, dings, and wear, otherwise fine condition. Part of the Apollo Command Module's sequential events control system, the controller was employed during spacecraft reentry to sense barometric pressure, automatically trigger firing pyrotechnics that released the Apex cover, drogue, pilot and main parachutes prior to splashdown. Apollo 4 was the first unmanned test flight of the Saturn V launch vehicle and used the S/C 017 Block I Command Module with modifications to test several important revisions for the Block II design, including a new heat shield as a result of the Apollo 1 disaster. Apollo 4 was a complete success, and the Command Module landed back on Earth about eight nautical miles from the target northwest of Midway Island in the North Pacific Ocean.
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