Astronauts working outside the International Space Station March 19 used an innovative laboratory device to detect how biological material may be spread in space. The experiment is a critical step in developing procedures to monitor and mitigate biological contamination in future missions to other worlds.

The successful spacewalk was the first-ever such use of the Lab-on-a-Chip Portable Test System, or LOCAD-PTS. The portable testing and analysis device, used on the space station since March 2007, is designed to rapidly detect and identify a variety of biological materials derived from various bacteria and fungi.

Before STS-119 mission specialists Steve Swanson and Richard Arnold exited the space station airlock to install new solar arrays that will help power the orbiting facility, astronaut Sandy Magnus swabbed their spacesuit gloves. The procedure was repeated when the astronauts returned to the space station.

The crew is analyzing the results using LOCAD-PTS, and will provide results next week, after Discovery undocks from the station to prepare for its journey home.

"This simple approach, designed to monitor the spread of biological material in space, takes very little crew time to perform and could prove to be a useful step in planning future human missions to the moon and Mars," said BAE Systems researcher Dr. Jake Maule, principal investigator for the LOCAD-PTS Exploration team.

As the spacewalkers worked, they came into contact with surfaces of the solar array truss segment, which were sampled and analyzed with LOCAD-PTS prior to their launch to space March 15 on space shuttle Discovery. While most surfaces of the hardware were clean before launch, slightly elevated levels of fungi were detected, particularly in the fabric gap spanners -- safety elements that literally span the gap between handrails, helping the crew move around the exterior of the space station as they work.

The suit gloves of Swanson and Arnold functioned as "swab" devices, picking up any bacteria or fungi, dead or alive, that remained on the gap spanners or other surfaces. Studying those samples will permit the LOCAD-PTS Exploration team to track biological materials before and after their journey from Earth to space.

Such measures will help development of a key capability for future human expeditions to the moon and Mars, said Mike Effinger, project manager for LOCAD at NASA's Marshall Space Flight Center in Huntsville, Ala., which leads the research. Its end goal: to establish procedures and create tools to monitor and restrict the spread of biological material on the moon and other worlds.

"Because spaceflight currently is limited to low Earth orbit, requirements don't exist yet in regard to biological contamination of other planetary surfaces by human missions," Effinger said. "This study seeks to begin development of test procedures that can be further developed on the moon in preparation for the human exploration of Mars."

The compact LOCAD-PTS device, which incorporates interchangeable cartridges, is designed to serve as a mobile laboratory requiring minimal resources. The handheld unit weighs just 2 pounds. It is driven by technology developed by Charles River Laboratories of Wilmington, Mass., and modified for space flight by NASA researchers at the Marshall Center.

The LOCAD-PTS Exploration experiment is funded by the NASA Science Mission Directorate's Moon and Mars Analog Mission Activities Program at NASA Headquarters in Washington.

For more information about the lab-on-a-chip technology and NASA's LOCAD project visit:

http://www.nasa.gov/mission_pages/station/science/experiments/LOCAD-PTS.html