Clusters of bacteria that are typically harmless on Earth can pose a health risk to astronauts when they find their way aboard space habitats. To combat that space microbe menace, scientists plan to launch an army of the bacteria Friday aboard the space shuttle Atlantis to test whether they can grow on novel new materials specially engineered to fight them.
The tiny space travelers will hitch a ride to space inside eight storage packs on Atlantis, each of which contains 128 vials. A similar control group of bacteria will remain on Earth, so that scientists can compare how the two groups fare.
"We know that gravity plays a key role in the development of biological systems, but we don?t know exactly how a lack of gravity affects the development of bacteria and biofilms," said study principal investigator Cynthia Collins, a chemical and biological engineer at Rensselaer Polytechnic Institute in Troy, NY.
Space bacteria can pose more than a health threat to astronauts. The microbes can affect hardware too.
Some bacterial biofilms, complex three-dimensional microbial communities, were responsible for increasing corrosion and damage a water purification system on the Russian space station Mir, NASA researchers said in a statement.
In addition to studying the bacteria growth, Collins and other researchers working on the Micro-2 experiment also plan to test a newly developed antimicrobial surface built by using nanotechnology.
?Using defense mechanisms found in nature, we have ?packaged? highly efficient bactericidal activity into functional surface coatings," said co-investigator Jonathan Dordick, also of Rensselaer Polytechnic Institute. "These surfaces do not cause toxic agents to be released, thereby providing a surface that is safe to humans but effective in destroying pathogenic bacteria."
Such surfaces might someday help prevent the formation or spread of bacteria in space and in hospitals.
Bacteria clusters, known as biofilms, exist both inside and outside the human body. Scientists have discovered that they?re mostly harmless, even if some are related to disease.
But toughened biofilms that survive hostile environments such as hospitals ? or confined locations like space shuttles ? can also become resistant to antibiotics. They might even become more potent just from living in microgravity.
A past animal study showed that the Salmonella typhimurium bacteria responsible for food poisoning and typhoid fever can become three times more dangerous when exposed to the zero gravity environment of space.
That presents a potentially huge problem for astronauts, because evidence has shown that humans suffer from weakened immune systems and become more vulnerable to infection in microgravity. Furthermore, researchers still don?t know exactly how microgravity affects the survival and spread of bacteria.
"This means while certain bacteria may be harmless on Earth, they could pose a health threat to astronauts on the International Space Station or, one day, long space flights," Collins noted.
Atlantis' space mission ? slated to be the shuttle's last-ever spaceflight ? is only expected to run about 12 days. The shuttle is due to launch Friday at 2:20 p.m. EDT (1820 GMT) from NASA's Kennedy Space Center in Florida and arrive at the space station on Sunday.
Atlantis will also deliver a new Russian science module to the space station, along with spare parts for the nearly complete orbiting laboratory.
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SPACE.com is providing complete coverage of Atlantis' STS-132 mission to the International Space Station with Senior Writer Clara Moskowitz in Cape Canaveral, Fla., and Managing Editor Tariq Malik based in New York. Click here for shuttle mission updates and a link to NASA TV.