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White shirt material being cleaned with cold plasma<\/p>\n
University of Alabama in Huntsville, Propulsion Research Center<\/p>\n<\/div>\n<\/figcaption><\/figure>\n<\/p>\n
Astronauts in space can\u2019t do laundry \u2013 but that may be about to change. And it could mean that those on longer-duration missions will be able to have more of the comforts of home on the surfaces of the moon or Mars.<\/p>\n
Aboard the International Space Station (ISS), astronauts tend to wear the same clothes for days on end and then pack them up to be thrown back towards Earth where they burn up in the atmosphere. That\u2019s all well and good for missions lasting a few weeks or even months, but it is not a viable solution for missions that last longer and that aren\u2019t regularly resupplied from Earth.<\/p>\n
<\/p>\n That\u2019s where Gabe Xu at the University of Alabama in Huntsville and Chelsi Cassilly at NASA\u2019s Marshall Space Flight Center in Alabama come in. They have developed a sort of \u201claundry gun\u201d that can be used to blast fabrics with cold plasma, killing off the microbes that cause unpleasant odours. Xu presented this work at the Astrobiology Science Conference in Wisconsin on 21 May.<\/p>\n Their device works by blasting a mixture of helium, air and water vapour with powerful bursts of electricity, which creates ions of oxygen. Those ions then seep into all the nooks and crannies of the fabric and are absorbed by microbes, killing them through what\u2019s called oxidative stress.<\/p>\n That\u2019s one of the benefits of this method over others, like exposure to UV light. \u201cThere are microbes that are UV resistant, but as far as we can tell from our experiments, there is nothing that is oxidative stress resistant \u2013 if you eat poison, it kills you,\u201d says Xu. Tests showed that the purple plasma beam reduced spore colonies on a scrap of cotton fabric from 250,000 colonies per millilitre to about 60,000.<\/p>\n It does that without damaging the fabric or creating any danger. \u201cWhen we think of plasma jets we think of lightning bolts or arc welding, which are typically very hot,\u201d says Xu. \u201cThis jet you can put your hand in, you could use it at home.\u201d<\/p>\n Using it at home wouldn\u2019t be very efficient, though, as the current version only sanitises a patch less than a centimetre wide at a time. Xu and Cassilly are now working on developing two more practical versions: a \u201cplasma washing machine\u201d where the plasma is piped into a chamber along with the fabrics being cleaned, and a dual plasma jet-vacuum cleaner that could be used on surfaces.<\/p>\n \u201cWhen you think about long-term habitats like the moon or Mars, astronauts will probably want a couch to sit on, somewhere nice, but they won\u2019t be able to have that unless they can clean it,\u201d says Xu. Plasma jets could finally make that happen.<\/p>\n Topics:<\/p>\n<\/section><\/div>\n