Project Viking Computer Command Subsystem Document Collection, 1969-1977
The collection documents the computer command subsystem of the Viking project. The originator of the documents varies. The Viking Orbiter was similar to the Mariner Mars 1971 spacecraft (Mariner 9), but used the Titan/Centaur boost vehicle. The major modification from Mariner Mars 1971 was the addition of a lander system which required a larger orbital propulsion system to accommodate trajectory corrections and orbit insertion about Mars, and also required a larger structure to support the additional mass of the lander. Another modification was the restructuring of the Viking Orbiter Computer Command Subsystem. On Mariner Mars 1969 and Mariner Mars 1971, maneuver relays were wired in with the Timing of Events relay in the Central Computer and Sequencer. The command systems aboard the earlier probes only knew what they were supposed to do, not what actually happened
Downloadable Archival Material, English, 1969