Stock Photo - Russian cosmonauts Alexander Misurkin (left) and Fyodor Yurchikhin, both Expedition 36 flight engineers, participate in a session of extravehicular activity (EVA) as work continues on the International Space Station. During the six-hour, 34-minute spacewalk, Misurkin and Yurchikhin replaced an aging fluid flow control panel on the station's Zarya module as preventative maintenance on the cooling system for the Russian segment of the station. They also installed clamps for future power cables as an early step toward swapping the Pirs airlock with a new multipurpose laboratory module. The Russian Federal Space Agency plans to launch a combination research facility, airlock and docking port late this year on a Proton rocket. Yurchikhin and Misurkin also retrieved two science experiments and installed one new one.