The Challenge
A prize of 10,000 Monero (XMR) will be awarded to the first team or individual who operates a 3D printer on the Moon. This 3D printer must use lunar soil as its print material and demonstrate that it can reliably produce custom mechanical components.
Guidelines for the competition were drafted on January 28, 2017 and are listed below.
- Guidelines
- Safely deliver a payload to the surface of the Moon.
- Deploy 3D printer and some method of gathering soil for its continued operation.
- Print a series of 3 test parts from lunar soil using an additive manufacturing technique which does not rely on external binding agents from Earth. The printer cannot rely on supplies from Earth for its continued manufacture of parts.
- Minor manipulation and/or assembly of parts will be required.
- The build volume of the printer must be at least 150x150x150mm with dimensional tolerances to within 0.2mm of specifications. This level of performance is comparable to mid-priced 3D printers currently available in the home market.
- The ultimate tensile strength of the parts must be greater than 10 MPa in any direction or about 1/3 that of common glass.
- The winning team must meet these objectives on or before December 19, 2022; or 50 years from when man last stepped foot on the Moon.
Feasibility: Funding
The value of cryptocurrencies increases exponentially with adoption. At the start of this competition in January 2017, the prize purse of 10,000 Monero was worth USD $120,000. As of August 2019, the prize purse of 10,000 Monero is equivalent to USD $800,000 (conversion rate). If the market adoption of Monero becomes similar to what the cryptocurrency Bitcoin enjoys today, then the 10,000 Monero prize purse will be roughly forty times more valuable, or greater than $50 Million, and would dwarf all existing space-based competition prizes. The size of the prize could also increase through donations or pledges made by additional backers. Any team in the competition may further offset their costs by pursuing crowdfunding, corporate sponsorships, or pairing their entry with another space-based competition.
What is Lunar Soil Made Of?
Glass and metal, mostly[3,4]. Aluminum, titanium, tungsten, and iron. Volatiles like ice and many useful trace elements[5,6,7]. Most soil particles are very fine with sharp angles, turned to powder through billions of years of meteoric impact. Older, more weathered particles have small bits of non-oxidized iron on their surface and imbedded within, making them efficiently heated with microwaves [8,9] and levitate in magnetic fields[10].
What Can Lunar Soil be Made Into?
Just about any solid object you can think of. Researchers have turned lunar soil simulant into gears, bolts, bricks, and bunkers[11,12,13,14,15]. They do this by selectively melting the soil in a desired shape and then cooling it until it hardens. Possible heat sources include lasers, microwaves, and concentrated solar, to name a few.
Many technologies in use by DIY maker communities and additive manufacturers can be extended with little modification to the lunar environment. Candidate technologies include selective sintering and fused deposition modeling. In selective sintering, a laser or other heat source is directed at a bed of powder which is partially melted and allowed to re-harden. Here’s a demonstration of how simple the process can be[16,17].
Fused deposition modeling is a type of 3D printing that you are probably most familiar with. Some material, typically plastic, is heated until it can be extruded out of a small nozzle. This extruded material is used to draw a 2D image on a flat surface. The height of the nozzle is then raised and another 2D image is drawn on top of the old. This process continues through many layers until a laminated 3D shape emerges. This technology was recently applied where small beads of optical glass acted as the raw print material[18], a substance not too different from lunar soil[19,20,21].
We can see from these examples that there are at least a few techniques for printing reliable parts from Moon dust. All major technical hurdles have been passed, now it’s just a matter of application-specific design.
Why a prize?
From the Orteig Prize sending aircraft across the Atlantic, to the Ansari XPRIZE sending private manned spacecraft to space, to the previous Google Lunar XPRIZE where teams were asked to drive a rover 500 m on the Moon, incentive competitions have simply been shown to work. Prizes are an effective way of directing the efforts of others towards a unified goal with potentially universal utility. Prizes encourage a specific goal and ask it of anyone who is able. A prize does not specify who will take the first revolutionary step, simply that someone should take that step.
Prizes are an excellent investment. The prize backers only spend their money if the competition garners a favorable result. The teams are compelled to initially spend their own resources to investigate several parallel designs. Incentive competitions have historically seen teams spend a combined $16 for every $1 used to fund the prize[22,23]; this represents a remarkable 16:1 return on your investment in terms of total R&D!
A competition also adds extraneous benefits. Humans tend to be thrilled by competition. They love the challenge, the race against another pack of humans. A need emerges to quickly find a solution and win at all costs.
Good solutions to the most difficult problems have been found under these conditions and frequently within shortened timeframes. We as a species need the ability to extract material resources from extraterrestrial sources as quickly as possible. Consider this incentive competition to be a fast, inexpensive, and exciting way for us all to realize that goal.
References
[1]http://www.parabolicarc.com/2010/03/15/send-1pound-payload-moon-950k/
[2]http://lunar.xprize.org/about/guidelines
[3]McKay, David S., et al. “The lunar regolith.” Lunar sourcebook (1991): 285-356.
[4]Noble, Sarah. “The Lunar Regolith.” (2009).
[5]Duke, Michael B., et al. “Development of the Moon.” Reviews in mineralogy and geochemistry 60.1 (2006): 597-655.
[6]Taylor, Jeff, Larry Taylor, and Mike Duke. “Concentrations of Volatiles in the Lunar Regolith.” (2007).
[7]Crawford, Ian A. “Lunar resources: A review.” Progress in Physical Geography 39.2 (2015): 137-167.
[8]Taylor, Lawrence, et al. “Lunar Dust Problem: From Liability to Asset.” 1st space exploration conference: continuing the voyage of discovery. 2005.
[9]Taylor, Lawrence A., and Thomas T. Meek. “Microwave sintering of lunar soil: properties, theory, and practice.” Journal of Aerospace Engineering 18.3 (2005): 188-196.
[10]Colwell, J. E., et al. “Lunar surface: Dust dynamics and regolith mechanics.” Reviews of Geophysics 45.2 (2007).
[11]Krishna Balla, Vamsi, et al. “First demonstration on direct laser fabrication of lunar regolith parts.” Rapid Prototyping Journal 18.6 (2012): 451-457.
[12]Fateri, Miranda, and Andreas Gebhardt. “Process Parameters Development of Selective Laser Melting of Lunar Regolith for On‐Site Manufacturing Applications.” International Journal of Applied Ceramic Technology 12.1 (2015): 46-52.
[13]Indyk, Stephen. Structural members produced from unrefined lunar regolith, a structural assessment. Diss. Rutgers University-Graduate School-New Brunswick, 2015.
[14]Lim, Sungwoo, and Mahesh Anand. “In-Situ Resource Utilisation (ISRU) derived extra-terrestrial construction processes using sintering-based additive manufacturing techniques–focusing on a lunar surface environment.” (2015).
[15]Goulas, Athanasios, et al. “3D printing with moondust.” Rapid Prototyping Journal 22.6 (2016): 864-870.
[16]Kayser, Markus. SolarSinter Project: www.markuskayser.com.
[17]Rietema, Menno-Jan. “Design of a solar sand printer.” (2013).
[18]Klein, John, et al. “Additive manufacturing of optically transparent glass.” 3D Printing and Additive Manufacturing 2.3 (2015): 92-105.
[19]Fabes, B. D., and W. H. Poisl. “Processing of glass-ceramics from lunar resources.” (1991).
[20]Fabes, B. D., et al. “Melt-processing of lunar ceramics.” (1992).
[21]Magoffin, Michael, and John Garvey. “Lunar glass production using concentrated solar energy.” Space Programs and Technologies Conference. 1990.
[22]Guthrie, Julian, Branson, Richard, and Hawking, Stephen. How to Make a Spaceship: A Band of Renegades, an Epic Race, and the Birth of Private Spaceflight. Penguin Press, September, 2016.
[23]https://en.wikipedia.org/wiki/Orteig_Prize