Exploring the Potential of Laser Sintered “Moon Bricks” for Future Lunar Colonization

Pausing to Examine a Laser-Sintered Sample

Author: Cole McCallum | Major: Mechanical Engineering and Physics | Semester: Fall 2024

For the last six months, I’ve been focused on evaluating the potential of laser-assisted regolith sintering as a method to replace pre-assembled habitats for lunar exploration. If successful, this technique could significantly cut down the costs of lunar missions by reducing the supply mass required for long-stay missions. So far, I’ve completed a proof-of-concept study to produce detailed miniature bricks and have developed, tested, and optimized a much larger test apparatus. The final phase of intensive data collection is all that remains for me to achieve my goals for this project.

Beginning Work

I began working with my mentor Dr. Shou after taking his Intro to Materials Course. He offered to tour our entire class around his laboratory, leaving me fascinated. I offered to help wherever I could and began completing minor experiments under supervision of Nahid Tushar, a PHD candidate in engineering. From here, Dr. Shou encouraged me to write a grant proposal and begin working on my own project. My interest in space travel led me to ultimately take up working on lunar regolith sintering. While there has been some research into this topic already, few people had actually studied the creation of 3D interlocking structures composed entirely of regolith. Dr. Shou took a very hands off approach when overseeing my research, having already seen me prove myself over my previous year in the lab. Nahid Tushar became my go to for quick advice whereas Dr. Shou helped me with the overall direction of my research.

Proof-of-Concept Study

My research journey began with a short proof-of-concept study. I learned to use essential laboratory equipment, including a 5-Watt laser and an FDM 3D printer. After mastering safety procedures, I designed and printed a small test basin with an aluminum base and plastic walls. I then added lunar regolith simulant to the basin and experimented with sintering individual layers by adjusting the laser’s intensity, speed, frequency, and width. If I make the laser too powerful, the regolith will be vaporized, whereas the powder will merely be heated by too low a wattage. This trial-and-error process took around 2.5 weeks, but I managed to find an optimal combination of factors for producing sintered parts. From here I needed to build a much larger device to hold the regolith powder in place before I’d be able to make anything useful.

Designing the Test Apparatus

Following the proof-of-concept, I embarked on designing a larger test apparatus capable of producing sintered parts of up to 8 cm width and height, and with up to 15-20 layers, each 0.5 to 1 mm thick. The initial design was straightforward but required custom-made parts, which proved impractical. I was advised to simplify the assembly process, leading to a design that utilized mostly off-the-shelf components. This revised design was pursued, and parts were ordered using my research grant budget. The apparatus was constructed with these parts and a single custom-designed “wall” made using UVR printing. Sadly, the printed part proved unreliable, so my mentor suggested using a laser cutter to create simpler wooden parts, which worked well. Below is a model showing my test apparatus attached to a z-axis linear actuator.

 

Overcoming Challenges and Moving Forward

Although I’ve been producing “male” and “female” interconnected parts since early October, I had to learn more about engineering design to ensure I’d collect good data while producing larger bricks. This led to several design and building iterations before I could create a functional, compact, and affordable device.  Despite these challenges, I successfully developed a device that meets my and my mentor’s design goals, paving the way for the final phase of data collection.

My mentor and I plan to dedicate time in early January to gather the required data. With a laser assisted process proven to fuse regolith together and a device that keeps the regolith in place, I’m optimistic that the last 6 months have put me in the best standing to succeed moving forward as I prepare to write a paper on this research. This project was certainly a challenge to work on, but I’m excited to share the results I find with both the university and the greater scientific community.