Decontamination system turns space station into life science laboratory
By David Szondy
June 16, 2014
The International Space Station (ISS) is perhaps the most artificial environment that human beings have ever taken up residence in. It’s not the sort of place where you’d want a lab accident, because you can’t run out the door and wait in the carpark for the air to clear, so NASA uses gloveboxes to keep the crew and equipment separate from dangerous contaminants. To increase this level of safety and expand the number experiments the station can carry out, the space agency is fitting one of the larger gloveboxes with an Ultraviolet Germicidal Irradiation (UVGI) system to to prevent potentially dangerous microorganisms from escaping.
The glove box is a simple, common piece of laboratory equipment that’s vital for safely conducting experiments on the ISS. Weightlessness is an exercise in things not staying put, and that’s not just the case with screwdrivers or socks, it’s also true for dust particles, gas, fluids, bacteria, and other dangerous substances. For that reason, much of the ISS is designed to keep people and machines separate from things that can damage them.
There are a number of gloveboxes onboard the station, from the small portable boxes to 9-cubic ft (254-l) Microgravity Science Glovebox (MSG). There’s even one for washing your hands. The MSG was developed by NASA and ESA, and has been in use on the ISS since 2002. It’s a sealed box equipped with gloves for safely handling hazardous materials and a pump to provide negative air pressure to make sure that nothing can blow back at the operator in the event of a leak.
The MSG is used for fluid physics, studying combustion in zero-G, materials science, biotechnology, and fundamental physics. According to NASA, the MSG has been a great help in weightless experiments, but one area that hasn't been open to investigation has been non-human biology because of the lack of adequate safeguards.
This is the reason for the new decontamination system that's being installed. Designed and built by Teledyne Brown, the system uses high-power, ultraviolet, light-emitting diodes (UV LEDs) to sanitize the interior of the MSG quickly and completely in only minutes. UV light is an extremely efficient sterilizing agent and is commonly used for decontaminating drinking water and fruit juices, and sanitizing hospital wards and laboratory equipment.
In addition to sanitizing, the new upgrade can remove airborne contaminants, and has a redesigned exchangeable glove selection. NASA says that not only will this UV sanitizing system allow the ISS to carry out microbial experiments, but it will also expand the station’s rodent science program.
"This application of UV has been an accepted practice for disinfection since the mid-20th century," says Lee Jordan, project manager of the MSG. "The DNA of the microorganism is disrupted by the UV radiation, leaving them unable to grow or reproduce. With this technology, it is possible to destroy more than 99.99 percent of all pathogens within seconds, without addition of chemicals, without harmful side effects, inexpensively, highly efficiently and absolutely reliably."