Technical Paper
Thermal Design and Flight Experience of the Mars Exploration Rover Spacecraft Computer-Controlled, Propulsion Line Heaters
2004-07-19
2004-01-2412
The cruise stage of each spacecraft (S/C) housed most of the hardware needed to complete the cruise from Earth to Mars, including the propulsion system. Propulsion lines brought hydrazine propellant from tanks under the cruise stage to attitude-control thrusters located on the periphery of the cruise stage. ...Thermal control of the propulsion lines was a mission critical function of the thermal subsystem; a frozen propellant line could have resulted in loss of attitude control and complete loss of the S/C. ...This paper covers the design, thermal testing and flight experiences with the computer-controlled thermostats on the propulsion line heaters. Flight experience revealed heater control behavior with propellant loaded into the system and during thruster firings that was not observable during system level testing.