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The Mars Exploration Rovers (MER), were launched in June and July of 2003, respectively, and successfully landed on Mars in early and late January of 2004, respectively. The flight system architecture implemented many successful features of the Mars Pathfinder (MPF) system: A cruise stage that transported an entry vehicle that housed the Lander, which in turn, used airbags to cushion the Rover during the landing event. The initial thermal design approach focused on adopting the MPF design wherever possible, and then concentrating on the totally new Rover thermal design. Despite a fundamentally sound approach, there were several salient lessons learned. Some were due to differences from MPF, while others were caused by other means. These lessons sent a clear message: thermal design continues to be a system engineering activity. In each major flight system assembly, there were excellent examples of this recurring theme.

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 Cassini spacecraft, NASA's mission to investigate the Saturn system, has undergone a system-level thermal balance test program to permit verification of the science instrument thermal designs in the simulated worst-case environments. Additionally, other objectives such as functional checkout, collection of thermal data for analytical model adjustment, and flight temperature transducer verification were also attained. In the interest of cost and schedule, transient off-sunpoint conditions were not tested. The test demonstrated that the required system resources such as heater power and radiator area were adequate. In the instance of the Cosmic Dust Analyzer, allowable flight temperature limits were violated, but this problem is being addressed without a significant impact to system resources or thermal design robustness. Finally, the thermal acceptability of a black Kapton “sock” was demonstrated for the magnetometer boom.