Massive Water Production from Cryogenic Icy Lunar Regolith by a Microwave Heating Method

Area of Science:

• Space Science
• Materials Science
• Engineering

Background:

• Water extraction from lunar regolith is vital for in-situ resource utilization.
• Traditional conductive heating is inefficient for massive water production due to lunar regolith's low thermal conductivity and harsh environment.

Purpose of the Study:

• To investigate the effectiveness of microwave heating for extracting water from icy lunar regolith at cryogenic temperatures.
• To reduce energy costs associated with massive water production.

Main Methods:

• Prepared hydrated lunar regolith simulant (LRS) with varying water content (1.96%-13.79%).
• Compacted samples into cylinders (70 mm diameter × 70 mm height).
• Utilized an integrated microwave heating system operating at 2.45 GHz with high (800 W) and low (400 W) power settings.

Main Results:

• Microwave heating demonstrated uniform sample heating and efficient water vapor escape from the center outwards.
• At 800 W, samples were nearly dried with an energy cost of 1.9-10.0 W·h/g and a water collection rate up to 1.57 g/min.
• Lowering power to 400 W extended initial heating but yielded comparable collection rates once water collection began.

Conclusions:

• Microwave heating is an effective technique for massive water production from icy lunar regolith.
• This method presents a viable and energy-efficient approach for future lunar engineering applications.