Two Russian cosmonauts have worked outside the International Space Station on an experiment to see how various materials and biological samples fare in the harsh environment of space.
A NASA television broadcast showed flight engineers Yury Malenchenko and Sergei Volkov left the station's airlock on February 3 for a 5-1/2-hour spacewalk.
The cosmonauts in a ceremonial move first cast off a flash drive into space containing video from last year's 70th anniversary of Victory Day, which commemorates the former Soviet Union's victory over Nazi Germany.
The flash drive eventually will reenter Earth's atmosphere and burn up.
Working 400 kilometers above Earth, Malenchenko and Volkov made their way to the site of a seven-year-old science experiment holding plant seeds, bacterial spores, fungi and other samples. The samples were to be removed and replaced.
The research is designed to test how well biological samples and various materials, such as coatings used on spacecraft, withstand the extreme temperature swings and high radiation of space.
They also planned to test a new glue that might prove useful in years to come on the station's exterior.