International Space Station (ISS)

Launched aboard the Space Shuttle Orbiter Atlantis on April 8, 2002, the STS-110 mission prepared the International Space Station (ISS) for future space walks by installing and outfitting the 43-foot-long Starboard side S0 (S-zero) truss and preparing the first railroad in space, the Mobile Transporter. The 27,000 pound S0 truss was the first of 9 segments that will make up the Station's external framework that will eventually stretch 356 feet (109 meters), or approximately the length of a football field. This central truss segment also includes a flatcar called the Mobile Transporter and rails that will become the first "space railroad," which will allow the Station's robotic arm to travel up and down the finished truss for future assembly and maintenance. The completed truss structure will hold solar arrays and radiators to provide power and cooling for additional international research laboratories from Japan and Europe that will be attached to the Station. STS-110 Extravehicular Activity (EVA) marked the first use of the Station's robotic arm to maneuver space walkers around the Station and was the first time all of a shuttle crew's space walks were based out of the Station's Quest Airlock. In this photograph, Astronaut Jerry L. Ross, mission specialist, anchored on the end of the Canadarm2, moves near the newly installed S0 truss. Astronaut Lee M. E. Morin, mission specialist, (out of frame), worked in tandem with Ross during this fourth and final scheduled session of EVA for the STS-110 mission. The final major task of the space walk was the installation of a beam, the Airlock Spur, between the Quest Airlock and the S0. The spur will be used by space walkers in the future as a path from the airlock to the truss.