Oct. 9, 2000 -- When astronaut Norm Thagard spent four months on the Mir space station, his hygiene routine was fairly basic.
He and his crewmates used two dry towels and one wet towel a day to freshen up. And even though Thagard, who was the first American to live on the now 14-year-old station, exercised at least once a day on board, he reports, “I never felt terribly unclean.”
One thing Thagard did notice, however, was the way the callused skin on the bottom of his feet began to flake off, since there was no pressure on his soles in microgravity.
“I came back with feet bottoms as smooth as a baby,” he says.
Cramped, Damp Places
While sweating and flaking skin may be harmless facts of life here on Earth, in the cramped quarters of a spacecraft or station, such bodily products can invite trouble. Given a moist opportunity, microorganisms inhabiting those shed body parts can flourish, multiply and, particularly if radiation levels are high, mutate.
“Microorganisms grow on everything on Earth or in space,” says Ralph Mitchell, a professor of applied biology at Harvard University. “But because a space station is such a tight space, there can be lots of nooks and crannies where organisms can grow.”
That reality, plus reports of funky smells and mildew-coated surfaces on the Mir space station, has prompted NASA to investigate how to deal with the problem. Its research, which accelerated with the establishment of an immunology and infection commission three years ago, is likely to take on more significance when two cosmonauts and one astronaut are scheduled to take up long-term residence of the International Space Station for the first time next month.
Learning how to combat infection in space will also become important should NASA launch a human journey to Mars in the future. Scientists now estimate a voyage to the Red Planet would require living in space for about two years.
“I’m sure we can get to Mars from an engineering perspective,” says William Shearer, a researcher for the National Space Biomedical Research program commissioned by NASA. “The question is will we be able to return live, healthy astronauts back home.”
Mixed Reports From Mir
Duane Pierson, the head of microbiology at NASA’s Johnson Space Center, points out that Mir has been a good litmus test for how well spacecraft can keep rampant bacterial and fungal colonies at bay. He says that when he and his team conducted tests on samples taken from the space station five years ago, they found it to be a “healthy environment.”
Still, Thagard recalls that at least one module of the Mir station was perpetually damp.
“It would have been a good place to view Earth, but all the windows were always too foggy to see through,” he says. “Even when you wiped the window clean, it would fog right up again.”
Thagard says he never noticed mildew buildup on the station, but the astronauts who followed him did. Michael Foale, who spent 134 days on the craft, told reporters in 1997 that “Mir has a lot of mold on the walls.” And Jerry Linenger, who spent nearly five months on the station, described in his book Off the Planet how the station had taken on a “mushroomy” smell.
Reports from a Russian microbiologist, Natalia Novikova, suggest that micro colonies might have since proliferated. Novikova told a Space.com reporter last June that a green mat of fungus and bacteria had begun eating away at the station’s windows and electronic equipment.
Shearer says such accounts are particularly worrisome because astronauts’ immune systems are known to weaken in space.
“The tremendous stress, isolation, lack of sleep and close containment in space can definitely stress the immune system,” Shearer says. “So they might be susceptible to microbes that otherwise wouldn’t bother them.”
He adds that a trip to Mars could pose even more problems since unexpected events like solar flares and gamma ray bursts could expose a crew to high levels of radiation. And radiation, he says, is known to weaken the immune system the same way HIV does, by depleting cells known as T-lymphocytes.
Radiation is also known to cause mutations in bacteria. And some have suggested any mutant bacteria that evolved in space could be difficult to battle, since the human body would have no experience with fighting the bug.
Shearer, whose team works independently of NASA, says he doesn’t know if astronauts and cosmonauts have been affected by infection in space since their medical records are kept confidential. Pierson maintains infection has not been a problem.
“I don’t known of anyone who reported environmental-related illnesses among crewmembers — and that’s the bottom line,” Pierson says.
Still, unconfirmed stories have trickled in from Russia describing cosmonauts who have contracted skin boils and infections while living on the Mir. And Shearer and Pierson both admit it would be irresponsible not to look into the matter.
“I know that in individuals we treat on Earth who have compromised immune systems, there are consequences,” Shearer says. “And I believe space can pose the equivalent situation.”
To combat infection on the International Space Station, Pierson says NASA is installing the most sophisticated air-filtering system available, a so-called hepafilter, on the station. The filter is so sensitive, he says, it can pluck microorganisms from the air. Pierson and other NASA scientists have also encouraged a much more basic approach to fighting scum buildup: required housecleaning.
As Thagard says, “That’s one job you can’t even avoid in space.”