Stock Photo - In the shirt sleeve environment of the International Space Station (ISS), astronaut Steven L. Smith (left) assists astronaut Jerry L. Ross with his extravehicular mobility unit (EMU) space suit. On the second space walk of the Space Shuttle Atlantis' STS-110 mission, astronauts Ross and Lee M.E. Morin completed the structural attachment of the newest component of the International Space Station, mating two large tripod legs of a 13 ½-ton truss to the station's main laboratory during a 7-hour, 30-minute period of extravehicular activity (EVA). The duo extended and bolted the final two struts of the new S0 (S-Zero) truss to the Destiny Laboratory, insuring that the centerpiece for the future expansion of the station would be permanently secured to accept additional trusses and solar array towers over the next year. The station will ultimately span some 350 feet from end to end, slightly longer than a football field. The work of the two mission specialists complemented that of the previous day by astronauts Smith and Rex J. Walheim.