International Space Station Commander Sergei Volkov (top) and Flight Engineer Oleg Kononenko (bottom) work with strella boom outside the orbiting laboratory in this image from NASA TV July 15, 2008. During their spacewalk, the cosmonauts will install a docking target and a science experiment among other tasks. REUTERS/NASA TV (UNITED STATES). FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS.