A team of scientists from the National Aeronautics and Space Administration, led by non resident Indian Dr Kasturi Venkateswaran, is spearheading a study that will advance the search for possible life on Mars.
NASA has built its spacecraft in rooms designed to minimise contamination by airborne particles because dust and its microbial passengers can foul instruments and invalidate experiments. If scientists someday find microbes on Mars, they will want to be sure that they aren't just hitchhikers from Earth.
The scientists' claim that they have discovered ultra-hardy organisms collectively known as 'extremophiles', something that has never been detected anywhere else.
"These findings will advance the search for life on Mars and other worlds both by sparking improved cleaning and sterilisation methods and by preventing false-positive results in future experiments to detect extraterrestrial life," said Dr Venkateswaran, who conducted the study at NASA's Jet Propulsion Laboratory in Pasadena in California.
The detection technology employed in this study will help NASA develop and monitor improvements. But the team says that it is still extremely difficult to eliminate all dust particles and microbes without damaging the electronic instruments.
As reported in the Microbiology Ecology, a journal of the Federation of European Microbiological Societies, Venkateswaran's team used a technology known as ribosomal RNA gene-sequence analysis to detect bacteria in clean rooms at Kennedy Space Center, Johnson Space Center and at the Jet Propulsion Laboratory.
This is the first time that this technology has been applied to NASA clean rooms. Clean rooms are considered extreme environments for microbes because water and nutrients are in extremely short supply.
Scientists found that both the total number of bacteria and the diversity of bacterial species were much higher than previously detected.
This has implications not only for NASA and other space agencies, but also for hospital operating rooms and industries such as semiconductor manufacturing, where cleanliness and sterility are critical.
Some bacteria are able to survive on the little moisture that the low-humidity air provides and on trace elements in the wall paint, residue of cleaning solvents and in the spacecraft material.