When astronauts go for spacewalks aboard the International Space Station (ISS), they not only have to share their spacesuits, but also the garment worn underneath. Known as the Liquid Cooling and Ventilation Garment (LCVG), it resembles a long underwear, and helps keep the astronauts cool and comfortable when they’re out working on the station. Now, the European Space Agency (ESA) is looking at ways to keep the LCVG cleaner and more hygienic. Since a fresh-out-of-the-laundry LCVG cannot be provided each time to astronauts on the ISS, the ESA plans to improve the antimicrobial properties in the garments. This will help keep them clean and fresh for longer.
The ESA has embarked on a project called Biocidal Advanced Coating Technology for Reducing Microbial Activity (BACTeRMA). A statement issued by ESA quotes Malgorzata Holynska, the agency’s material engineer as saying, “Spaceflight textiles, especially when subject to biological contamination – for example, spacesuit underwear – may pose both engineering and medical risks during long duration flights. We are already investigating candidate materials for outer spacesuit layers so this early technology development project is a useful complement, looking into small bacteria-killing molecules that may be useful for all kinds of spaceflight textiles, including spacesuit interiors.”
Explaining in detail about the garments spacewalkers wear, the ESA states that the first item they put on is a (disposable) “maximum absorbency garment” diaper. Then they put on their own “thermal comfort undergarment,” followed by the LCVG, which is worn next to the skin. It incorporates liquid cooling tubes and gas ventilation to keep the wearer cool and comfortable.
On the ISS, astronauts clean their hands and bodies with no-rinse cleaning solutions and dry shampoo. However, cleaning clothes is not possible because that would require a lot of water, states NASA, adding that there are four options as gar as astronauts’ undergarments are concerned — wear it again, turn it into a shooting star, grow plants with it, and feed it to bacteria.
To prevent biological contamination, usually, antimicrobial fabrics that use silver or copper are used. However, over time, these metals cause causing skin irritation. So, the ESA is seeking the support of Vienna Textile Lab, a company that produces textile dyes using naturally occurring bacteria. “They have exclusive access to a unique bacteriographic collection. Those microorganisms produce so-called secondary metabolites. These compounds are typically colourful, and some exhibit versatile properties: antimicrobial, antiviral and antifungal,” said BACTeRMA project scientist Seda Ozdemir-Fritz of the Austrian Space Forum.
The project will focus on developing textile finishes with these antimicrobial properties. It will also expose the processed textiles to perspiration and radiation to see how they react. To simulate conditions astronauts encounter in space, lunar dust will be added to the mix.
If the project is successful at arriving at a solution, it could make the sharing of the garments in space much more pleasant and hygienic.