In-Flight Performance of the Mars Science Laboratory Spacecraft Cruise Phase Thermal Control Systems

Abstract

The National Aeronautics and Space Administration’s Mars Science Laboratory (MSL) mission will land a robotic rover on the surface of Mars for a two-year exploration mission. During the deep space transit from Earth to Mars, the rover will reside in a compact and static mechanical assembly stack called the Cruise phase configuration. While the majority of the Mars entry, descent, landing and surface-specific hardware subsystems are dormant during the nine-month transit from Earth to Mars, all of the spacecraft’s thermal control systems are utilized to maintain hardware within allowable temperature limits. Of these systems, a mechanically-pumped fluid loop runs throughout each of the main spacecraft stages and is used to both reject spacecraft waste heat loads and provide survival heating to components. A second fluid loop located within the rover is used to thermally control the surface avionics and science instrument suite. Additionally, a large number of electrical film heaters are employed throughout the spacecraft to provide survival heating to individual spacecraft components. This paper presents a description of the various MSL cruise phase thermal control systems and reviews their in-flight performance over the first six months of the mission.