Stock Photo - KENNEDY SPACE CENTER, FLA. -- The STS-110 crew heads for the Astrovan and a ride to Launch Pad 39B for the launch scheduled at 4:40 p.m. EDT (20:40 GMT). From left-foreground are Mission Specialists Jerry L. Ross and Rex J. Walheim; left, second row, are Mission Specialists Steven L. Smith, Lee M.E. Morin, Ellen Ochoa; Pilot Stephen N. Frick; and Commander Michael J. Bloomfield. STS-110 is the 13th assembly flight to the International Space Station, carrying the S0 Integrated Truss Structure and Mobile Transporter (MT). On the 11-day mission, the mission features four spacewalks to attach the S0 truss, which will become the backbone of the Space Station, to the U.S. Destiny Laboratory. The MT, a space railcar, is attached to the truss segment and will make its debut run during the flight.