for National Geographic News
The seemingly spic-and-span rooms where NASA assembles its spacecraft aren't quite as clean as experts had thought, a new study suggests.
A surprising diversity of bacteria thrive in at least three of the space agency's so-called clean rooms, genetic testing has revealed.
NASA experts go to great lengths to keep these rooms immaculate by sealing them from the outside environment, continually filtering the air, and cleaning the insides.
The aim is to protect the spacecraft's surface from dust and bacteria, while protecting other planets from Earthly microbes. (Related news: "Mars Life May Be Contaminated by Spacecraft, Experts Warn" [July 26, 2005].)
In the past, the most common method of finding bacteria was to capture samples, take them back to a lab, and try to grow a culture.
However, of all the bacteria out there, "the fraction that you can grow in a lab is about one percent," said study leader Kasthuri Venkateswaran of NASA's Jet Propulsion Laboratory at the California Institute of Technology.
The rest we have not yet found a way to grow outside of their native environments.
So Venkateswaran and colleagues applied a sensitive technique that can find traces of genetic material from bacteria—even from those species that won't grow in the petri dish.
"To get a more global picture, we need[ed] to use DNA fingerprinting," he said.
The researchers took samples from clean rooms at three NASA sites: the Jet Propulsion Laboratory in Pasadena, California; the Kennedy Space Flight Center in Cape Canaveral, Florida; and the Johnson Space Center in Houston, Texas.
The team spotted nearly a hundred different kinds of bacteria in the clean rooms, and about half of them were new to science. Some of the bacteria were common culprits, such as the Staphylococcus, bugs that thrive on human skin.
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