In terms of sheer coolness, very few things come close to NASA – especially if you happen to be an avid Sci-Fi fan like me. With that in mind, two stories that emphasise the critical role materials selection plays in the quest towards
In terms of sheer coolness, very few things come close to NASA – especially if you happen to be an avid Sci-Fi fan like me. With that in mind, two stories that emphasise the critical role materials selection plays in the quest towards space exploration have caught my eye.
First up, from Wired, is a story dubbed ‘Nasa’s wild fabric is basically chain mail from the future’. My inner geek was delighted to read that ‘To minimize the weight of its payload, NASA has experimented with inflatable materials that can balloon into habitats, and tangles of lightweight rods that can shift shape on different terrains. Now, designers at NASA’s Jet Propulsion Laboratory have developed a foldable fabric that could pull triple duty during outer space missions.
‘Researchers at JPL spent the last two years developing a metallic space fabric made of interlocking stainless steel squares. It looks like chain mail, but unlike the ancient armor, NASA’s fabric isn’t welded together. Instead a 3-D printer extrudes stainless steel as a continuous sheet of material with different properties on each side. From the front of the fabric, rows of shiny, flat squares can reflect heat and light. On the back, a series of interlocking loops help the fabric absorb heat. Together, the single piece of material acts like a super-strong shield, protecting astronauts and spacecrafts from outer orbit’s deadly obstacles.’
Unlike its namesake, this chain mail is far more flexible whilst retaining its strength. In the words of JPL, this focus on revolutionary new materials aims to ‘increase the science we can do per kilogram’, which is not only exciting in itself, but could pave the way to making human exploration to other worlds that much closer.
To the stars!
And that brings me nicely to the next article, which focuses on how Velcro-like threads could aid spacecraft engines in reaching Mars. Published by Scientific American, the article addresses the issue of heat and explains that ‘today’s composites are made by layering woven mats of silicon carbide fibers and filling the space between them with a porous ceramic. But existing composites can crack under the high pressures that occur in engines because the fibers slip against one another and pull out of the ceramic.
‘In a possible breakthrough, scientists at Rice University and the NASA Glenn Research Center have developed “fuzzy” silicon carbide fibers whose surfaces resemble a microscopic version of Velcro. The fibers, described recently in Applied Materials & Interfaces, would be less likely to slip or pull out of a surrounding ceramic medium because their fuzzy tangles lock them together…
‘The team tested the fuzzy fibers’ strength by embedding them in a transparent, rubbery polymer—and found these composites to be four times as strong as those made with smooth threads. NASA research engineer and study co-author Janet Hurst says the team now wants to test the new, curly fibers in a ceramic medium. They also want to make fibers with a fuzzy boron nitride nanotube coating because it is strong and shields the fibers from damaging oxygen exposure.’ It will be interesting to see how these fibers hold up during further testing.
Turning up the heat (shield)
Designing a spacecraft capable of withstanding the environmental stresses of entering a planet’s atmosphere is a topic that captures the imagination of many engineers. Our recent webinar on Mars lander heat-shield material selection explores the nature of advanced material selection, and how the visual and interac