Spacewalk under way

HOUSTON, Dec. 22 (UPI) -- Two members of the International Space Station crew have begun a spacewalk to install experiments and an electromagnetic energy probe, NASA said Monday night.

Expedition 18 Commander Mike Fincke and Flight Engineer Yury Lonchakov also plan to take photographs and relocate an experiment that measures thruster exhaust plumes, the space agency said on its Web site. The spacewalk began at 7:51 p.m. EST and was scheduled to last just over six hours.

Lonchakov, the lead spacewalker, is making his first spacewalk. Fincke is making his fifth spacewalk.

The electromagnetic energy measuring device they are installing, called a Langmuir probe, could help determine whether electromagnetic energy played a role in pyrotechnical separation bolts on Russia's Soyuz spacecraft. The bolts are suspected in the investigation of ballistic -- steeper than normal -- entries of the Expedition 15 and Expedition 16 Soyuz spacecraft, the National Aeronautic and Space Administration said.

The spacewalkers plan to install the Expose-R experiment package on the Zvezda service module. The package contains nine European Space Agency astrobiology experiments, designed to expose biological samples to the harsh conditions of space, NASA said.

Meanwhile, Flight Engineer Sandra Magnus installed a baseband assembly and a light housing assembly in the Japanese logistics module's pressurized section.