Advanced Cooling Technologies, Inc. in collaboration with Honeybee Robotics is developing a Thermal Management System (TMS) to facilitate ice extraction from icy-lunar regolith and efficient ice collection in a cold trap tank. The TMS has two main technologies 1. Thermal corer; and 2. Variable Conductance Heat Pipe (VCHP) based cold trap tank, along with other connecting technologies like rotary union and pumped fluid loop. The thermal corer is essentially an auger with minichannels for ice extraction through which heat transfer fluid circulates. A prototype thermal corer of length 17.3 cm and inner diameter 5 cm was fabricated with stainless steel. Performance testing of the thermal corer showed more than 60% ice extraction efficiency. Sublimation was the primary mode of ice extraction followed by liquid-vapor phase change. On the other hand, the VCHP cold trap tank was demonstrated to show ice collection by rejecting heat from incoming vapor to the cold plate simulating deep space heat rejection. During this mode, the VCHP was operating as a heat pipe. Additionally, the de-icing mode to melt ice from the heat pipe surface was demonstrated by activating the VCHP mode by blocking heat transfer to the cold plate. Finally, a system-level sizing analysis was undertaken by developing a mass-energy balance model with the following deductions: the rover weighing about 115 kg can extract 0.48 kg of ice with a total operational time of 4 hours. To achieve an ice-mining rate of 2.78 kg/h, about 24 thermal corers are required. In addition, sensitivity analysis was performed to determine the influence of system parameters like ice extraction efficiency, mining-processing site, etc.
Hota et al. (Sun,) studied this question.