Sintering Stardust
Sintering Stardust: Two High School Students Search into Microwave Sintering as a Possible Solution to Lunar Regolith Dust
By Abigail Glover
Currently pursuing a degree in Mechanical Engineering, Aydin Cunningham delved into regolith simulants during his junior year of high school when he stumbled upon a science book about lunar resources.
The book focused on the many challenges associated with utilizing various in-situ materials on the moon and what would need to be prepared in advance for humanity’s return. However, one such issue stood out to the inquisitive high school student. What was an effective way to manage lunar regolith dust? Lunar regolith dust is a fine grit of jagged silica grains mixed with other minerals like iron. The dust accumulates a static charge which makes it stick to space suits and equipment where it can cause abrasion damage. Cunningham's curiosity was piqued by the book’s mentioning of using microwaves as a possible solution to this issue and thought it may be possible to create dust-free “hardscape” areas around equipment and lunar base air locks. He and his partner Leland Jacobson set out to explore a microwave sintering process that could turn the loose lunar dust into solid and durable masses.
The focus of their experiment soon expanded from Lunar dust mitigation to the possibility of using sintered Lunar regolith to create construction materials.
Their approach utilized Exolith Lab’s Lunar Highlands Simulant (LHS-1), combined with micron-sized iron particles to better replicate lunar regolith, and a 1200W, 2.45GHz home microwave. Over the course of 6-7 months, Cunningham and Jacobson conducted numerous tests, meticulously observing various microwave configurations, different increments of microwave exposure, and varying iron concentrations in the regolith simulant. After each microwaved sintering sample was collected, the two then tested the overall strength of the material using a hammer and press. Through their experimentation, the two discovered that a 5% iron concentration microwaved for approximately 5 minutes yielded the most promising results, producing a solid block of lunar regolith slag.
In their concluding remarks, Cunningham and Jacobson highlighted that the key to their success lay in using two layered porcelain crucibles, emphasizing the importance of insulation in the sintering process. They also noted that while micron-sized iron particles were initially considered ideal, their efficacy was diminished due to their size. Nanophase iron particles, as seen on the moon, have the potential for much greater efficiency. Nevertheless, their efforts showed that sintering lunar regolith into cohesive masses of silicon/obsidian, iron, and dust aggregate was achievable within mere minutes.
The microwave sintering technique Cunningham and Jacobson explored holds immense promise for transforming loose lunar dust into robust construction materials. This study, and others like it, could potentially pave the way for constructing various structures on the Moon, from bricks and sheets to tiling. Additionally, the concept of sintering the lunar dust into solid ground opens possibilities for creating stable foundations on the dusty lunar surface.
As humanity continues to explore the prospects of space exploration and colonization, new ways to examine viable solutions like Cunningham's could become the foundation for future endeavors beyond our home planet.