While toiling outside the International Space Station (ISS), astronauts depend on spacesuits not only to stay alive in their airless environments, but also to stay cool during their rigorous, hours-long work to maintain the orbital laboratory.
Engineers in Europe are adapting the same cooling systems used inside those spacesuits to aid firefighters, industrial workers and others who face scorching temperatures on Earth. Dubbed the Safe&Cool program, the work is part of technology transfer effort by the European Space Agency (ESA).
"The main goal is to keep the temperature and humidity levels inside [work] suits at a comfortable level when operating in harsh environments," Stefano Carosio, Safe&Cool project manager for ESA at the Italian firm D'Appolonia, told SPACE.com. "We used in particular the concept of cooling vests worn by astronauts for thermal management."
ESA officials said that an average of about 1,500 cases of heat stroke occur each year in Europe due to the work garments that are incapable of sufficiently shedding excess heat or moisture. An estimated 50,000 are subjected to heat stress, which can lead to injury due to loss of concentration, they added.
A cooler worksuit
Before stepping into their NASA spacesuits, astronauts don a one-piece mesh garment lined with water-cooling tubes. The suit makes up about 6.5 pounds (2.9 kilograms) of the more than 100-pound (45 kilogram) U.S.-built Extravehicular Mobility Unit (EMU), which can be subjected to temperatures of up to 250 degrees Fahrenheit (121 Celsius) in full sunlight, according to NASA descriptions.
On Earth, Carosio and his team wove the spacesuit inspired water-cooling tubes into a fabric composed of materials tailored to keep the skin feeling dry while siphoning off moisture through suction channels. A water-binding polymer coats the fabric, absorbing excess moisture or releasing it during "flash events," when the cooling system is overwhelmed, to mimic the human body's sweating process.
Once assembled, the warped and knitted fabric forms the central layer of a traditional three-layer protective garment, the ESA said.
"The idea was to combine advanced polymers to bind humidity and cooling systems, and to reduce temperature in order to recreate an integrated air conditioning system," Carosio said, adding that the system can be adapted to suit its wearer's purpose. "It is definitely a matter of functional design."
More work needed
But clearly work remains to be done.
Safe&Cool researchers hope to their project will yield protective clothing robust enough to meet directives set by the European Union. The technology has already found uses in competitive racing in clothing developed by the firm Grado Aero Espace, with Spanish Moto-GP driver Sete Gibernau donning a cooling vest while Formula-1 McLaren mechanics donned whole suits in a trial.
"We did explore them," McLaren spokesperson Clare Robertson told SPACE.com.
McLaren officials said pit mechanics wore the specialized cooling suits during a practice run to test their effectiveness, but found that the standard, fire-retardant Nomex suits were still a better choice for their needs.
Meanwhile, ESA officials believe the cooling technology could eventually prove a viable alternative for sportswear as well as protective gear, with the Poland-based firm TAPS testing its potential to regulate temperatures in car sears and other transports.
"Further functionalities are being investigated," Carosio said.
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