Two Russian cosmonauts are spacewalking for the second time in less than a week, AP reported. Fyodor Yurchikhin and Aleksandr Misurkin ventured out of the International Space Station on Thursday morning. They stepped out Friday as well. This time, the cosmonauts will replace a laser experiment on the Russian side of the orbiting outpost. They also will check six antennas attached to Russia\'s main compartment. On Monday, an antenna cover came off and floated away. Russian space officials want to know which antenna it came from. NASA, meanwhile, has suspended all U.S. spacewalks while the investigation into last month\'s near-drowning continues. An Italian astronaut\'s helmet filled with water during a spacewalk. He barely made it back inside.