Astronauts to clean space underwear with microbes
Sharing your unwashed underwear with another person isn’t ideal.
For astronauts on board the International Space Station (ISS), performing a spacewalk requires that they share not only the spacesuits, but also a piece of clothing that’s worn underneath, known as the liquid cooling and ventilation garment (LCVG).
Access to a freshly laundered LCVG isn’t an option on the ISS, but technicians with the European Space Agency (ESA) are taking steps to improve the antimicrobial properties in LCVG materials to keep these shared garments clean and fresh for longer.
In a new two-year project called Biocidal Advanced Coating Technology for Reducing Microbial Activity (Bacterma), ESA researchers are collaborating with the Vienna Textile Lab, a private biotechnology company in Austria that produces fabric dyes from bacteria. Compounds generated by these bacteria can also make textile fibres more resistant to certain types of microbes. Astronauts on the ISS keep their hands and bodies clean with no-rinse cleaning solutions and dry shampoo, but laundering clothes, including underwear, would require too much water, and is simply not possible. Nor is there enough room on the ISS for astronauts to pack a fresh change of clothes for every day of their mission.
When it comes to dirty underwear, astronauts don’t have the luxury of being squeamish, and may wear a pair more than once. American astronaut Don Pettit wrote that he changed his underwear once every three or four days when he was on the ISS. And when Japanese astronaut Koichi
Wakata tested bacteria-resistant underwear coverings in space in 2009, he wore one pair for about a month. When clothing becomes too soiled or smelly for an astronaut to wear, it is either returned to Earth as rubbish or is packed up into a capsule, ejected into space and burnt up in Earth’s atmosphere.
LCVGs are only worn during spacewalks, but astronauts are working harder than usual when they wear this communal undergarment. An LCVG is very formfitting, covering the limbs and torso, and it keeps astronauts cool during the extreme physical exertion of working in the vacuum of space. An adult diaper is worn underneath, in case the astronaut needs to relieve themselves during a spacewalk. Gas ventilation draws moist air away from extremities, while flexible tubes that are sewn into the garment circulate cooling water around the body and help to remove excess heat, maintaining a comfortable core body temperature. ESA scientists were already investigating candidate materials for upgrading outer spacesuit layers, so this new initiative “is a useful complement, looking into small bacteria-killing molecules that may be useful for all kinds of spaceflight textiles, including spacesuit interiors,” said ESA material engineer Małgorzata Hołynska. Scientists will test the performance of antimicrobial properties in the new textiles by exposing them to sweat, lunar dust and radiation to simulate conditions that could accelerate aging and deterioration of the fabric in space.
MINDY WEISBERGER