There is currently a significant amount of interest in Mars exploration by NASA to send a series of orbiting spacecraft and landers to Mars over the next decade. For the science and engineering systems that will land on the surface of Mars, there is a great challenge for thermal control. The Pathfinder mission will place a lander with an autonomous rover on Mars in July 1997; and the Mars '98 mission set will have an orbiter and surface lander and surface penetrators. In the planning stages are additional landers and rovers, leading up to a Mars sample return mission for 2005 launch opportunity. The 8 torr CO2 atmosphere and cryogenic temperatures are a unique thermal environment. The environment constrains the types and duration of missions that can be conducted and the thermal insulation required. All these factors add to a difficult challenge to design thermal control systems for Mars surface exploration. Current thermal insulation control approaches will be described and the needs for future missions.