Thermal Management System for Comet Sample Return

Advanced Cooling Technologies, Inc. (ACT) proposes to develop a thermal control system for a sample return capsule utilizing evaporation of a consumable working fluid that is vented to the environment. The preliminary vision of the proposed concept (and system) architecture is approximately based on the Orbiting Sample Capsule integrated with the Earth Entry Vehicle for Mars Sample Return (MSR). The proposed concept consists of several annular/concentrical (not necessarily spherical and continuous) chambers (layers) surrounding the sample chamber as follows: a Vapor Chamber containing the working fluid in saturated state, which is vented to provide evaporative cooling at the wick-sample chamber interface, a bladder or bellows based Flexible Liquid Reservoir for liquid storage, displacement and delivery to the vapor chamber, a Compressed Gas Chamber that continuously provides the pressure required to passively drive the liquid into the vapor chamber and a Heat Guarding Chamber that allows the vented vapor to flow towards the ultimate exit and further collect and remove any incoming environmental heat leaks. In addition, the system will include liquid delivery headers, temperature and pressure sensors and solenoid and check valves.The proposed concept/system has the following advantages: lightweight, passive, low energy consumption (mostly for sensors and valve actuation), simple, low cost, scalable, allows set point change remotely and it can generate precooling on demand. It is applicable to sample-return (SR) missions that require landing on large bodies (e.g., Luna, MSR), as well as particulate-class SR missions (e.g., Genesis, Hayabusa) or touch-and-go missions to relatively small asteroids or comets (e.g., OSIRIS-Rex, Hayabusa2).During the Phase I program, ACT will develop a sub-scale consumable-based thermal control system prototype and demonstrate its capability through mathematical modeling and experimental measurements.