- The International Space Station (ISS) wasn't empty when
the first crew arrived in 2000. A welcome party was waiting to greet them.
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- Russia's Mir Space Station wasn't lifeless when it made
that fiery plunge into the Pacific Ocean in 2001. Mir was teeming with
life after the last crew abandoned ship.
-
- Ignore the official crew counts on the next space shuttle
flight. Hitchhikers ride each shuttle into orbit.
-
- Microbes have been the first, last, and most numerous
inhabitants of manned space vehicles since Yuri Gagarin blazed that new
frontier in 1961.
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- Viruses, bacteria and fungi get into space vehicles during
assembly on Earth as workers breathe, cough, and touch surfaces. Crews
bring more.
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- Microbes not only survive in space, they thrive. NASA
experiments in 1968 on Biosatellite II first showed that microbes grow
better in space than on Earth.
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- Mir became a showcase for the nasty situation. With cramped
living quarters and a hapless climate control system, Mir's air was so
damp that moisture condensed on the walls.
-
- Human beings on Earth constantly shed dead skin, hair
and tiny particles of mucus in coughs and sneezes. In space, the flurry
becomes a blizzard.
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- American astronaut Norm Thaagard, who spent four months
on Mir, noticed that callused skin on his feet flaked off because there
was no pressure when he stood.
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- In the damp air, Mir's microbes thrived on the cast-offs.
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- Mir went 15 years without a thorough cleaning. American
astronauts complained bitterly about the filth and stench. Michael Foale,
who spent 134 days on Mir in 1997, described interior cabin walls slick
with a film of mildew.
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- The microgravity conditions, and higher radiation levels,
fostered mutations or changes in the microbes' genetic material. New forms
of the microbes appeared - slightly different from those people encounter
on Earth.
-
- In 2001, Tulane University researchers confirmed that
the environment in Earth-orbit makes some bacteria mutate and become more
virulent, or dangerous in causing infections.
-
- Russian cosmonauts often complained about coughs, skin
boils and other infections after returning to Earth. Nobody knows whether
they were caused by bacteria that evolved on Mir, or unsanitary conditions
on Earth.
-
- By the late 1990s Mir's littlest cosmonauts and astronauts
were literally eating parts of up the station.
-
- One Russian scientist described "a green mat"
of fungus and bacteria growing on cables and electronic components. The
fungus produced acid wastes that damaged electrical equipment and even
etched and fogged a window, clouding cosmonauts' view of space.
-
- The counterparts of these "germs from space"
now are growing inside Mir's successor, the $60-billion ISS. NASA, which
built ISS with partners from a dozen other countries, learned lessons from
Mir's problems.
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- ISS has an upgraded climate control system, for instance,
that filters out many microbes and keeps the humidity low. Drinking water
is super-purified - a good thing since the source includes recycled astronaut
urine and breath.
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- Astronauts swab down surfaces with germicidal wipes,
and take other precautions to discourage their microscopic crewmates.
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- NASA also is monitoring the space station for signs that
microbes are mutating into new strains that could pose a health danger
to astronauts. Long space flights weaken the human immune system, making
astronauts more vulnerable to infections.
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- Could astronauts bring alien germs back to Earth, trigging
a plague from outer space?
-
- Stifle those smirks. Who knows?
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- The risk may be bigger later in the 21st century. Astronauts
may be returning from three-year missions to Mars, and lunar colonists
may be heading back to Hometown USA for a vacation.
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- ISS and its crews, big and little, are the laboratory
and volunteers in a real-life experiment that may help provide the answer.
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- http://www.knoxstudio.com/shns/story.cfm?pk=MEDICAL-09-04-02&cat=AH
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