When the Starship Enterprise went roaming through the galaxy, the captain and crew had to be vigilant. There might be Klingons, Romulans, disembodied intelligences composed of pure energy. What they never seemed to worry about was the threat of festering scum underneath the toilets or behind the sinks. But maybe they should have, according to Cynthia Collins and Jon Dordick.
Collins and Dordick are scientists at Rensselaer Polytechnic Institute in Troy, NY. — a microbiologist and a nanotechnologist, respectively — and when the space shuttle Atlantis lifts off on Friday for the shuttle program's final flight, their experiment could be crucial to the health of future astronauts. There's evidence from earlier spaceflights that virulent bacteria such as E. coli and salmonella can grow stronger and faster in microgravity. Given enough time, they can form biofilms, slimy mats of bacteria that are highly resistant to antimicrobials. If the films get inside the body, riding on catheters or other medical equipment, the human imune system may be powerless against them. That's true even when the immune system is functioning at its best, but in space, for reasons nobody fully understands, the body's disease defenses are weaker.
"It's anecdotal," admits Dordick, "but over the years, Russia's Mir space station evidently became coated with biofilms."
On a week-long shuttle mission, the danger is minimal. But biofilms could pose a huge problem for passengers aboard the International Space Station or, someday, on a voyage to Mars. "More than 60 percent of infections people get in hospitals," says Collins, "are caused by biofilms." If it's impossible to keep bacteria out of a hospital environment that's supposed to be spotless, it's equally hard to keep them out of space. "You can't very well sterilize an astronaut," says Dordick.