NASA documents 2001 Mars Odyssey's integrated spacecraft propulsion subsystem as a hydrazine/nitrogen-tetroxide chemical system with one approximately 640 N main engine for major maneuvers, four approximately 1 N attitude-control thrusters, and four approximately 22 N turning thrusters. A gaseous-helium tank pressurizes the fuel and oxidizer tanks. This record represents the complete installed spacecraft propulsion subsystem and preserves the main-engine, attitude-control, turning, and pressurization boundaries without asserting an individual engine product model.