IN SPACE - SEPTEMBER 13: In this handout photo provided by NASA, STS-115 mission specialists Astronauts Daniel C. Burbank (right) and Steven G. MacLean, representing the Canadian Space Agency, work at part of the integrated truss system on the International Space Station on September 13, 2006. Construction resumed on the orbital outpost during the second of three scheduled space walks for the Shuttle Atlantis and International Space Station crew members.