The techniques that will one day allow us to colonize Mars are progressing little by little, but the road is still long.
3D printing is one of those common denominators that we find everywhere in science fiction. It’s a very useful narrative sleight of hand for writers, especially in space, as it helps offer a relatively plausible explanation for loads of elements of futuristic folklore. And this very promising concept could soon be invited into the real world.
Various players, starting with the space agencies, have been interested in it for years. The International Space Station, for example, is already equipped with a high-performance 3D printer. ESA also plans to to recycle its metal structures and use them to 3D print parts directly in space.
There are also even more ambitious projects that intend to use this approach to deploy a proper infrastructure on other planets. For example, NASA is exploring this approach as part of the Moon; several teams of researchers have already proposed using the materials present in the dust and soil of our satellite to build real buildings for future astronauts.
And these are not very long-term projects that will take decades to see the light of day; we even find traces of it in the Artemis program which should bring astronauts back to the Moon around 2025. It includes a 3D printed lunar bunker project, imagined in partnership with the start-up AI Space Factory. If all goes well, it will be able to serve as an operational base for the Americans present on the spot.
A “Martian” ceramic with interesting properties
Today, a research team based at Washington State University is proposing a new project of this kind, but this time centered on Mars. These researchers began by producing what they call “ simulated regolith “. In essence, it is simply a synthetic material specially designed to replicate the composition of Martian soil as closely as possible.
They then attempted to produce a building material by mixing it with varying amounts of metal. Everything was heated to 2000°C by a special 3D printer for small-scale testing. The objective: to assess the viability of the structures thus built.
The first test, with 100% simulated regolith, produced mixed results. The machine was able to print the desired shapes, but the material properties left something to be desired. It turned out to be friable and prone to fractures. It would therefore be very poorly suited to the construction of an airtight structure.
But this first test was not useless. Instead of being used for the structure itself, the researchers say that this material could make an excellent coating. It would suffice to cover machines with it to protect them from oxidation. A relatively thin layer, even partially fissured, could also protect humans from the deleterious effects of cosmic radiation. Again, this will be absolutely essential to consider an extended stay away from Earth.
The researchers therefore tried another approach. Their idea was still to use the regolith as an additive, but not as a base for the whole structure. Here it served them to reinforce other materials. At the end of the process, the most promising result turned out to be a titanium alloy reinforced with 5% of this famous simulated regolith.
Unlike pure lunar regolith, the ceramic produced displayed very interesting mechanical properties. During their tests, this material did not present the slightest trace of cracks. This indicates that it is relatively stable under Martian conditions. It was also stronger and lighter than pure titanium. In addition, it did not produce bubbles when cooling. This last point is very important in order to be able to control the printing process with satisfactory precision.
The other interesting point is that titanium is a relatively common element on Mars according to NASA. But for now, this is just a proof of concept; there is almost no chance that this alloy will be used to build the future colony of Elon Musk, for example.
Work still in its infancy, but nonetheless important
On the other hand, this work shows that it is already possible to imagine an infrastructure built from raw materials that will be available in abundance on Mars. In the long term, the ideal would be to find a material composed mainly of this ubiquitous regolith on the Red Planet, then to improve it using other elements that are also locally accessible. Also, it’s not just about infrastructure. This ability to produce valuable alloys directly from local resources will likely be critical to the survival of future interplanetary missions.
In conclusion, this work is still in its infancy, but it is a small step in the right direction. And that’s good news, knowing the potential challenges of this technology.
” In space, 3D printing is something that has to happen if we want to consider crewed missions, because you really can’t take everything you need from Earth. And if we forgot something, we can’t go back to get it back “, explains Professor Amit Bandyopadhyay in the press release from his team.
It will therefore be interesting to follow the progress of this work, which could lead to the first Martian construction within a few decades.