Flight Engineer Yury Lonchakov (left) and Commander Mike Fincke conduct a spacewalk. Credit: NASA TV

(PhysOrg.com) -- Tuesday's spacewalk with Expedition 18 Commander Mike Fincke and Flight Engineer Yury Lonchakov concluded at 5:11 p.m. EDT when the Pirs docking module airlock was closed. The spacewalk concluded ahead of schedule, lasting 4 hours and 49 minutes.

The Exposing Specimens of Organic and Biological Materials to Open Space (Expose-R) experiment was installed on the universal science platform mounted to the exterior of the Zvezda Service Module.

The spacewalkers also removed straps, or tape, from the area of the docking target on the Pirs and docking compartment. The tape was removed to ensure it does not get in the way during the arrival of visiting Soyuz or .

Fincke and Lonchakov later took photos of the exterior of the Russian portion of the station to document its condition after a decade of operation in the harsh environment of space. The photos will be used to assess the condition of the outer surfaces and structural elements of the station, including active components such as and vents.

Tuesday's excursion was the 120th in support of assembly and maintenance.

Fincke and Lonchakov will return to Earth April 7 in their Soyuz TMA-13 spacecraft now docked to the station. Fincke and Lonchakov have been aboard the orbiting laboratory since October 2008.

Provided by NASA