Development of Lunar Vehicle and Payload Thermal Control Systems for Extreme Lunar Environments

Lunar night poses a significant thermal challenge to small, low power payloads, rovers and landers. Due to the slow rotation of the lunar surface, the environmental temperature drops to below 100K for approximately 14 earth days. In order to enable long duration science missions on the lunar surface it is necessary to maintain the electronics above survival temperature during the lunar night. nbsp;The Apollo astronauts went to moon during early Lunar morning, which is a relatively benign thermal environment.nbsp; In contrast, Lunar Landers and Rovers must be able to survive and function over multiple Lunar Day/Night cycles. It has been estimated that for every watt of power generated by batteries during lunar night an additional 5kg of mass is required. nbsp;Surviving multiple lunar cycles without the use of active power sources will require advanced thermal management techniques.In this SBIR program, Advanced Cooling Technologies, Inc. (ACT) will develop a toolbox of thermal devices that can be combined into fully passive Thermal Management Systems (TMSs) for Lunar Landers and Rovers.nbsp; There are four parts of a TMS: (1) Heat Acquisition, collecting heat from electronics, (2) Heat Transport, (3) Heat Rejection, and (4) Heat Storage. The heat transport must use a Variable Thermal Link, which transports heat with minimal Delta;T during the day, and passively shuts down at night, minimizing heat losses.nbsp; Over the past decade, ACT has been developing five types of variable thermal links, Variable Conductance Heat Pipes (VCHPs) with warm and cold reservoir, VCHP Loops, and conventional and 3-D printed Loop Heat Pipes (LHPs) with Thermal Control Valve (TCVs).nbsp; On the proposed program, ACT will develop LHP TCVs and a high-power thermal switch.nbsp; ACT and Astrobotic will conduct trade studies to optimize designs for Landers and Rovers, and then fabricate and test a Lander and Rover concept in a relevant environment.