1 hour ago
1
The prototype ‘laundry gun’ in action during a fabric treatment test.
Astronauts heading on long missions to Mars could face a surprisingly ordinary problem: how to keep their clothes clean without wasting precious water. Scientists at the University of Alabama in Huntsville, working with NASA's Marshall Space Flight Center, have developed a small device that could offer a solution.
Nicknamed a “laundry gun”, the prototype shoots cold plasma at fabric to reduce the number of microbes living on astronauts' clothes and other soft surfaces. In early tests, the device reduced microbial spore colonies on fabric by more than 75%. Unlike a washing machine, it does not use large amounts of water or cleaning chemicals.
The researchers say the technology could eventually help astronauts stay healthier during long missions where every kilogram of supplies and every drop of water matters.
How the ‘laundry gun’ works
The device uses cold plasma, an electrically charged mixture of particles that can be produced without heating the fabric to extremely high temperatures. When the plasma reaches the material, energetic particles interact with gases such as oxygen and water vapour in the surrounding air. These reactions create highly reactive molecules that can attack and damage the outer membranes of microorganisms. The process is designed to reduce bacteria and other microbes living on fabric rather than physically wash away dirt.
The current prototype is about the size of a pen and treats only a small patch of material at a time.Early laboratory tests produced promising results. Researchers found that plasma treatment reduced spore colonies on a fabric sample by more than 75%. The result suggests the technology could substantially lower the microbial load on clothing and other soft surfaces. That could be important inside a spacecraft because astronauts live together in a confined environment for long periods, giving microorganisms plenty of opportunities to spread.
However, the result does not mean the device kills 75% of every microorganism on every type of fabric. More testing is needed to determine how well the technology works against different microbes and under realistic spaceflight conditions.Despite its catchy name, the laundry gun is not a replacement for a washing machine yet. The plasma can help kill or reduce microbes, but it does not remove visible dirt, food stains or other substances from clothing.
The researchers have even noted that the device will not remove stains such as coffee marks. Its main purpose is sanitisation, which could nevertheless be valuable during long missions. Astronauts could potentially reuse clothing for longer if microbial contamination can be controlled without repeatedly washing the fabric in water.
Why Mars missions need a new approach
Laundry is much harder in space than it is on Earth because water is a limited and valuable resource.
Astronauts on the International Space Station do not have a conventional washing machine. Instead, clothing is worn multiple times and eventually discarded or replaced with supplies delivered from Earth. That approach is possible because the ISS regularly receives cargo. A crew travelling to Mars would face a very different situation.
The journey would last months and there would be no practical way to regularly send replacement clothes from Earth.
Reducing the amount of clothing, water and cleaning supplies required could therefore make a major difference.
The device could also sanitise spacesuits and tools
The researchers are looking beyond everyday clothing. The same plasma technology could potentially be used to sanitise spacesuits, tools and other equipment before astronauts leave a habitat and operate on another world. This could have implications for planetary protection, where space agencies try to prevent Earth-based microorganisms from being transported to other worlds.
The technology could also potentially be used on bedding and other soft surfaces inside a spacecraft or habitat.
These applications remain under development, but they show why the researchers see the device as more than a simple alternative to laundry.
The plasma comes with an ozone problem
The technology also creates a challenge that researchers must solve before it can be safely used inside a spacecraft. Plasma interactions with oxygen can produce ozone, which can be harmful at high concentrations.
That is particularly important in a spacecraft where the same air is continuously circulated and reused. The researchers are therefore working on a filtration system that could remove excess ozone generated during treatment.
A future space-ready version would need to balance effective microbial reduction with safe air quality, low power consumption and minimal impact on the fabric being treated.
Researchers want a larger version
The current pen-sized prototype is too small to clean or sanitise an entire item of clothing efficiently.
It can treat only about a square centimetre at a time, meaning an astronaut could not realistically use it on a complete shirt or spacesuit in its present form. The team plans to develop a larger handheld device that can cover more material while remaining compact enough for use inside a spacecraft. Researchers will also need to test how repeated plasma exposure affects different fabrics over long periods to make sure clothing does not deteriorate after repeated treatments.
Space laundry is already being explored
The plasma gun is one of several efforts to solve the laundry problem for future space missions. NASA and its partners have investigated low-water laundry technologies and specialised detergents designed for space. Procter & Gamble's Tide Infinity detergent, for example, has been developed specifically for future space use, while other projects have explored washing and drying systems designed to use very little water.
The plasma approach is different because it focuses primarily on killing microbes rather than washing clothing in the traditional sense. A future Mars habitat could potentially use several of these technologies together rather than relying on one system.
It could reduce the supplies needed for Mars
The biggest advantage of the plasma approach could be the amount of material it saves. Long-duration missions have to account for every kilogram of equipment, every litre of water and every item of clothing carried from Earth. If astronauts can safely reuse clothes for longer while keeping microbial contamination under control, they may need fewer replacement garments and less cleaning equipment. The researchers say plasma treatment could therefore reduce the mass of supplies required for a human mission, particularly one travelling to Mars where resupply would be extremely difficult.
