Researchers at Washington State University published a paper with the results of a study on using Martian regolith for 3D printing in the International Journal of Applied Ceramic Technology. The National Science Foundation (NSF) funded the study.
The researchers ran tests using powder that contained as little as 5% of a material meant to simulate Martian regolith. 100% Martian regolith was also used, but proved too brittle to be useful for 3D printing. The 5% Martian regolith blend, which also included a titanium alloy, proved the strongest.
A high-powered laser heated the material to 2,000 degrees Celsius. The superheated material was run through a powder-based 3D printer, which the researchers used to 3D-print objects in a variety of sizes and shapes. Then they tested the strength and heat resistance of the objects.
The 100% Martian regolith material cracked as it cooled. However, engineer and paper co-author Amit Bandyopadhyay said it might be useful as a coating for the radiation shields that will be critical on Mars. The 5% Martian regolith material (95% titanium alloy) was the strongest and did not crack or bubble. The 5% regolith mix also demonstrated better properties than pure titanium alloy.
The lesson here? Have a ready source of titanium alloy. However, shipping it from Earth to Mars could get expensive. The paper cited the high cost of just launching things into Earth orbit. Using NASA’s Space Shuttle cost $54,000 per kilogram to put stuff in orbit (and was an inefficient way to launch satellites anyway). A dedicated launch on a SpaceX Falcon 9 can send up to 8,300 kilograms into geosynchronous orbit for $67 million – which works out to about $8,072 per kilogram.
(Okay, I get it, I wish Elon Musk would just stick to playing with his rockets and cars too. Even allowing for the occasional “oops,” at least he’s not throwing rocket stages into the ocean and letting them rust if he can possibly help it.)
In-situ resource utilization (ISRU) can save even more money. ISRU involves using local resources instead of having to haul everything with you when you go on an exploration mission. Many of the successful explorers of the past used it. They could hunt, fish, and forage and knew how to get away with traveling light.
Hunting, fishing, and foraging won’t be an option on Mars, though agriculture will. That’s right, you could really grow potatoes on Mars, lol.
As importantly, using local materials to make habitats is an option. 3D printing on other worlds like the Moon and Mars looks increasingly possible, which means future Martians might be able to expand their habitats. You could even send some material-gathering robots and 3D printers in advance instead of having to send all the components of their habitats to Mars as Dr. Robert Zubrin’s Mars Direct plan (shown in the below video) proposed. That is, of course, assuming that the 3D printers don’t need a lot in the way of close supervision, like some “desktop” 3D printers can.
“In space, 3D printing is something that has to happen if we want to think of a manned mission, because we really cannot carry everything from here,” said Washington State University engineer and paper co-author Amit Bandyopadhyay.
It’s already possible to 3D-print houses on Earth in as little as 48 hours, as seen in the below video. Just load up the additive manufacturing machine (which is the fancy term for 3D printers) with concrete and let it have at it. This could be great for things like natural disaster recovery if it takes off.
Somebody’s playing with the idea of using local material to 3D print houses in this video:
If it’s possible on Earth, then why wouldn’t it be possible on Mars? Well, you have to account for the idea that Martian “soil” has a different makeup. Technically, it isn’t even soil. It’s full of perchlorates – the stuff they make chlorine-based cleaning solutions out of – and hasn’t been “processed” by life-forms like bacteria and worms.
(There might be bacteria deep under Mars’ surface, but scientists don’t know for sure. Even the Viking probes, which tried to find proof of biology-based metabolism, gave us some confusing readings.)
Which means that we might have some learning to do before we can 3D-print habitats out of it. However, we’re working on it. NASA posted a challenge to help refine techniques to 3D print large structures on Mars a few years ago.
ICON also ran a program called Mars Base Alpha, which had four people living in a simulated 3D printed Mars habitat for a year. It was part of a NASA study to understand the challenges of living on Mars (and probably produced some interesting psychological studies).
The work of the Washington State University researchers could be a good first step toward figuring out what needs to be done before local materials can be used to make habitats on Mars. There will probably still be some materials, like titanium alloy, that we need to take with us when we go to Mars. However, 3D printing habitats on Mars could help reduce costs.