Keeping your underwear clean on the Moon
When astronauts return to the Moon they will be bringing along a new generation of spacesuits, designed to withstand the harsh conditions of the lunar surface. But in keeping their human occupants safe and comfortable, these suits might also become a fertile environment for harmful microbial life – especially as astronauts will potentially be sharing suits with one another.
As part of a larger ESA effort called PExTex, assessing suitable textiles for future spacesuit design, the Austrian Space Forum is leading a project called BACTeRMA, looking into ways to prevent microbial growth in suit inner linings.
The most obvious hazards are the external ones: moonwalkers venturing out of lunar bases will have to contend not only with hard vacuum but also wild temperature extremes, space radiation and highly abrasive dust – which partially jammed the seals of Apollo spacesuits within just a few hours of exposure, while compromising their outermost layers.
That’s why the PExTEx (Planetary Exploration Textiles) project, led by France’s Compagnie Maritime d’Expertises, COMEX, has been assessing novel textiles that did not exist during the Apollo era, such as high-strength Twaron material.
Guided by planetary surface architectures such as the US-led Artemis initiative, the PExTex team have been testing materials for a spacesuit that could withstand at least 2 500 hours of surface use. That involves subjecting them to numerous tests overseen by PExTex partner the German Institutes of Textile and Fiber Research, DITF.
These have included ultra-high vacuum exposure, electrical discharge, temperature shifts and rubbing with simulated moondust – as well as exposing textiles to nuclear accelerator radiation conducted at the MedAustron facility in Austria.
Meanwhile another PExTex partner, the Austrian Space Forum (Österreichisches Weltraum Forum/OeWF), has focused on keeping the insides of spacesuits safe and healthy, through its ‘Biocidal Advanced Coating Technology for Reducing Microbial Activity’, or BACTeRMA for short.
“Think about keeping your underwear clean; it’s an easy enough job on a daily basis, thanks to detergent, washing machines and dryers,” explains ESA materials and processes engineer Malgorzata Holynska. “But in habitats on the Moon or beyond, washing spacesuit interiors on a consistent basis may well not be practical.
“In addition, spacesuits will most probably be shared between different astronauts, and stored for long periods between use, potentially in favourable conditions for microorganisms. Instead we needed to find alternative solutions to avoid microbial growth.”
Traditional anti-microbial materials such as silver or copper might cause skin irritation in the close quarters of a spacesuit, and are likely to tarnish over time.
Instead the BACTeRMA team turned to so-called ‘secondary metabolites’ – which are chemical compounds produced by microbes to protect themselves against competitors or other environmental factors. Typically colourful in appearance, these compounds often have antibiotic qualities.
OeWF worked with BACTeRMA partner the Vienna Textile Lab, which possesses a unique ‘bacteriographic’ collection, to develop biocidal textile processing techniques, such as dying cloth with these bacterial metabolites. These materials were then exposed to radiation, moondust and simulated human perspiration to test their durability.
As a result, the BACTeRMA partners have gained valuable insights into the effectiveness and suitability of antimicrobial substances, such as violacein pigment and prodigiosin – known for its pinkish hue on dirty surfaces – on various textile materials.
Gernot Grömer, OwEF Director, comments: “The findings of PExTex and BACTeRMA lay the foundation for future developments in the areas of antimicrobial treatments and the integration of smart textile technologies. Additionally, these projects could have broader implications for the textile industry, by demonstrating the feasibility and importance of developing innovative textiles with specialized properties.
“The Austrian Space Forum is currently integrating the newly developed textiles in its spacesuit simulator. In March 2024 these materials may undergo their first analog field test as part of our simulation of a crewed Mars mission in Armenia during the AMADEE-24 field campaign.”
German ESA astronaut Matthias Maurer expressed his appreciation for the PExTex and BACTeRMA results: "Space technology, funded by ESA and developed in Europe, is a crucial step to bolster the expertise of European industry and academia for future human and robotic planetary exploration."
Austrian Space Forum
OeWF is a space research organisation following a citizen scientist approach: different experts across various science domains come together in the OeWF to work on space topics, with a special focus on spacesuit technology.
The idea for the two-year BACTeRMA project was proposed by OeWF in cooperation with the Vienna Textile Lab as subcontractor, through ESA’s Open Space Innovation Platform, seeking out promising ideas for space research from any source.