Feature

Text Size

ISS 'Mates' SWAB Deck
09.19.07
There is no five second rule on the space station!

Cleanliness is not just the dirt one can see. It’s also a matter of bacteria and parasites. That’s why -- even though there is no floor -- there is no five second rule on the space station.

Though most micro-organisms are harmless, and some are even beneficial, there are those that can adversely affect crew health and performance during a mission.

iss014e09413 -- Expedition 14 Commander Michael Lopez-Alegria As part of routine operations, space station crew members sample and culture air, water, and surfaces to determine if additional cleaning is needed.

Image at right: Astronaut Michael Lopez-Alegria conducts a Surface, Water and Air Biocharacterization (SWAB) air sampling in the Destiny laboratory. Credit: NASA

But, most microbes can’t be cultured. Plus, allergens, such as those tiny dust mites that invade your home, and microbial toxins produced by bacteria, fungi and algae, have never been thoroughly studied in spacecraft environments.

This week, Expedition 15 Flight Engineer Clay Anderson will gather samples using new collection techniques that improve the quality of the samples taken on the station. The samples are part of an experiment called the Surface, Water and Air Bio-characterization, or SWAB.

One new technique is collecting air samples through a gelatin filter that can retain particles as small as viruses. Also, a DNA preservative will be used for water and surface samples improving the possibility of recovering microbial DNA for study.

Crew members began collecting SWAB samples last fall during Expedition 13 and will stop at the end of Expedition 15 in September 2007. The information gathered from the yearlong study will help track changes in the station’s microbial “community” as spacecraft visit and the new modules are added.

As the samples are returned to Earth, scientists at Johnson Space Center and the University of Nevada in Las Vegas also will use advanced molecular techniques to evaluate the microbe samples. These techniques are similar to those used by law enforcement to identify suspects by analyzing and comparing DNA. Using DNA amplification methods, NASA scientists will be able to “fingerprint” bacteria, identify organisms based on bacterial and fungal ribosomal DNA, and identify specific microbial genes using targeted DNA probes.

“Our current operational techniques don’t detect organisms like Legionella, the microbe responsible for Legionnaire’s disease,” according to co-investigator Mark Ott of Johnson. “SWAB should give us a great deal of insight on the risk of exposing the crew to those types of organisms during a mission.”

That kind of information could help flight surgeons keep astronauts healthy during future trips to the moon and beyond.

The study also could provide insight into "sick building syndrome," the incidence of sudden increased illnesses at a workplace within a fairly close time frame.

Lynnette Madison
Johnson Space Center