A Summary of the Cassini Spacecraft Thermal Performance from Launch Through Early Cruise

Cassini, NASA's mission to investigate the Saturnian system was launched successfully on October 15, 1997. The cruise period from launch until Saturn arrival takes the spacecraft through a wide range of solar/thermal environments (0.67 astronomical units [AU] to 10 AU). The thermal control approach, which consists of thermal design features and operational constraints, must therefore maintain hardware temperature limits throughout this wide range of environments.

The off-sun exposure flight experience with interplanetary spacecraft at relatively close heliocentric distance is very limited. Cassini's ability to perform off-sun maneuvers relies heavily on the large thermal capacitance of the spacecraft's central body and the relatively short off-sun durations required for these maneuvers. The post launch execution of the first trajectory correction maneuver (TCM-1) was the first opportunity to validate the spacecraft off-sun capability and to enhance the thermal math model simulation capability.