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THIS STORY HAS BEEN FORMATTED FOR EASY PRINTING
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Astronauts vs. fungus
Orbiting spacecraft turns out to be food for aggressive mold By Gareth Cook, Globe Staff, 10/1/2000
Squinting to set his sights on the passing Earth below, this space explorer instead focused on a thick living mat that had made its way up the window's hard quartz surface, nearly obliterating any view.
A microbiologist, Natalia Novikova, eventually identified the growth as an aggressive space fungus. And since then, she's had her hands full examining the various forms of fungi found growing aboard the ship. The aging Mir, it turns out, is nearly overrun with the stuff. Visitors have found numerous fungal patches with hues between green and black, feeding behind control panels, slowly digesting the ship's air conditioner, communications unit, and myriad other surfaces. Pull out an insulation panel on Mir, and you'll probably find fungus.
And in the heavy radiation of space, Novikova and others said, these fungi could mutate into more virulent forms, possibly harming future space travelers, or even be carried back to Earth to wreak havoc as they join the many earthbound varieties that relentlessly attack metal, plastic and glass surfaces.
Scientists are discovering that ''biodegradation,'' the term used to describe microbial damage to materials, is a far greater problem than previously thought. Fungal infections could explain why electronics fail more often than expected, and microbes, along with acid rain, are assaulting famous landmarks from the Taj Mahal to the Acropolis to the cathedral in Cologne. Just last month, China hired a Belgium company that said it would launch a three-year program to rid the 40 varieties of mold eating away the famed 2,200-year-old army of terra cotta warriors. The mold has attacked 1,400 of the 8,000 life-sized statues of soldiers and horses that were found in the tomb of China's first emperor, Qin Shihuang, outside the city of Xian.
But there's no one to call to combat space mold, and NASA is suddenly treating the topic seriously. Decades of science fiction notwithstanding, it now seems the great threat to space exploration comes not from technologically advanced alien races, but from the same lowly fungi that attack dorm-room refrigerators. With the $60 billion International Space Station under construction, and more ambitious missions to the moon and Mars being considered, the Mir infection has shown that fungi are surprisingly destructive, giving off corrosive agents like acetic acid that damage equipment and release toxins into the environment.
Spacecraft ''are closed systems, and there is very little room for error,'' said Ralph Mitchell, a professor of applied biology at Harvard who has helped NASA come to terms with the microbial threat. ''Within days, all of the astronauts share all of the same microflora ... like children in kindergarten.''
Viewed under a microscope, many fungi look harmless, beautiful even, with long threads weaving a living filigree. But, unchecked, they happily destroy the things we build.
Mitchell, in research for NASA, said that his team placed fungus on plastics the agency was considering for the International Space Station, and watched the effects. Over time, the plastics bubbled, released fumes, and broke off in thin strips. Placed on metals, he said, fungi can plunge through the surface, weakening it with pits and microscopic fissures.
On space missions, the potential problems multiply because of increased radiation that can cause the fungi to mutate into more dangerous forms. Francis Cucinotta, manager of the radiation health office at NASA's Johnson Space Center, said he published a scientific paper in 1995 that found that about one-tenth of 1 percent of bacterial spores would mutate after a year of the kind of radiation experienced on a mission to Mars.
The problem, he cautioned, was poorly understood, and nobody could say how many of the mutations would pose a threat.
But astronauts are also less able to fight off infections, doctors said, especially on long missions. The stresses placed on their bodies, including weightlessness, psychological pressure, and trouble sleeping, can all degrade the immune system.
''If the microflora is altered into some kind of superbug, and the astronaut's immune system is weakened, it could cause quite a problem,'' said William Shearer, a professor of pediatrics and immunology at the Baylor College of Medicine, and the team leader in charge of immunology for the National Space Biomedical Research Institute.
US astronaut Jerry Linenger said that when he was on Mir in 1997, he found ''an overgrowth of fungus.''
Linenger, who is a medical doctor and holds a doctorate in epidemiology, used a standard NASA test to determine fungal counts on surfaces. For the shuttle, he explained, the samples would be placed in a medium so their growth could be tracked over several days. But on Mir, he said, he couldn't do the count because the container was overgrown in half a day.
Linenger, author of ''Off the Planet,'' a book about his experiences on Mir, said that he did not see any evidence that fungi or bacteria on the craft caused health problems. But he added that the station had ''a strong smell of fungal contamination'' - a smell he called ''mushroomy'' in his book - and that ''there were areas you wouldn't want to stick your hand in.''
According to Novikova, who heads the Microbial Protection Laboratory of the Russian government's Institute for Biomedical Problems, Mir's problems first came to light with the finding of fungus on the porthole in 1988, and have been an issue ever since.
The fungi that did the damage, Novikova said, included members of the genera Aspergillus, Penicillium, and Cladesporium - all very common on Earth.
In July, a Web site called
Space.com described some of Novikova's findings, but the results did not gain wide attention.
NASA officials said that wherever humans go, they bring a certain amount of fungus with them. They said they had not seen evidence of biodegradation on the International Space Station, but they have put into place an ''aggressive'' prevention program. On a visit to the station this summer, astronauts spent hours lifting out panels to search for evidence that colonies were causing damage.
''Because of this issue on Mir, it has led us to be more aware of the need to do these inspections more frequently,'' said Kyle Herring, a NASA spokesman.
There is no evidence that fungi have ever affected the health of the crew, or threatened the integrity of critical systems, said Jeffrey Manber, president of MirCorp, the Amsterdam-based company that has leased the rights to use Mir. He said that the situation hasn't threatened MirCorp's business ventures, which include sending the winner of a sequel to the television show ''Survivor'' to the station.
MirCorp has undertaken a $5 million project to upgrade Mir's environmental control systems, Manber said.
When the space race began with the Russians' launch of Sputnik in 1957, it was seen as an engineering challenge. But as experience accumulates, scientists say they are coming to appreciate more and more that it is a serious biological challenge as well. NASA's Cucinotta said that there are a host of ''basic questions that NASA must answer before it can go to Mars.''
But for Linenger, who was almost killed by a fire during his stay on Mir, the lure of exploration will always outweigh dangers such as microbial infestation. Climbing into a rocket is like ''climbing onto a pile of explosives,'' he explained. ''There are just too many other things to worry about.''
This story ran on page A01 of the Boston Globe on 10/1/2000.
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he history books will never record it, but life in outer space was discovered about 12 years ago by a Russian cosmonaut as he was gazing out a window of the space station Mir.