Making Materials Ready for Mars
Norman Wagner, a professor of chemical and biomolecular engineering at the University of Delaware, talks about materials testing in space for space missions to Mars.
(Inside Science) -- “A mission to mars. We really want to develop materials that will be able to protect astronauts, both on the way and when they’re on the surface of the planetary surface. And these advanced nano-structure materials require science that we don’t have yet. So, that drives a need for scientific understanding and how homogeneous gels can be created, and how we can control that through the processes of these materials.
“So there are a lot of challenges to working on Mars. Martian dust, because there isn’t a lot of erosion, is extremely sharp. So, you have very sharp sandlike particles everywhere, and the dust gets in everything. And that dramatically degrades the soft goods, the habitats, the space suits. Science was all about nano-particle systems that form homogeneous gels, and how we can study the aging behavior of those gels, [and] how their mechanical properties change.
“The example of the sunscreen is a great one, because you have a material, and as it ages, the structure that was put into that to keep it as a cream and a homogeneous material, starts to collapse and fall apart. And as [that happens,] you get a liquid layer and it separates. Now when you put it on your skin you’re also not necessarily getting the cover[age] of the nano-particles that are absorbing the UV. So, particles in sunscreen are actually very similar to what we were studying in our work. If you get the aging right, as we’ve shown, you can actually strengthen the material. Think of it as a nano-composite, where we take the existing or best suit materials that we can make now in terms of textiles, and treat them with these nano-particle gels in such a way that they dramatically work synergistically to reinforce each other. And we’ve shown this in the laboratory; we’re demonstrating this on the International Space Station.
“The low Earth orbit environment, is actually a very hostile environment. There’s extremes of temperatures. There’s also, because we’re at the very top end of the atmosphere, there still are oxygen radicals which are corrosive and reactive. And occasionally there are micro-meteorite strikes. The International Space Station is armored in many different ways to protect against that and this is a candidate material for doing that.
“We will deploy various types of formulation of our configurations that would be used on the outer part of the Martian space suit, to put that on the front end of the International Space Station, on a test station called [Materials International Space Station Experiment] ‘MISSE,’ which is a materials test station designed to expose things to this environment. And then it will be brought back down to Earth for further diagnostics and study. And partly we just want to prove out that these materials can withstand the tremendous rigors of lower Earth orbit. Obviously, that’s a different environment than on Mars, but we can’t test it on Mars until we get there.”
