The STS-127 crew members eagerly head to the Astrovan for the drive to Launch Pad 39A.

The STS-127 crew members eagerly head to the Astrovan for the 3.4-mile drive to Launch Pad 39A. From left are Mission Specialists Dave Wolf, Tim Kopra, Tom Marshburn, Julie Payette of the Canadian Space Agency, and Christopher Cassidy, Pilot Doug Hurley and Commander Mark Polansky. At the pad, the astronauts will complete their suitup and enter space shuttle Endeavour for the 7:13 p.m. EDT liftoff. This is the fourth launch attempt for the STS-127 mission. The first two launch attempts on June 13 and June 17 were scrubbed when a hydrogen gas leak occurred during tanking due to a misaligned Ground Umbilical Carrier Plate. Mission managers also decided to delay tanking on July 11 for a launch attempt later in the day to allow engineers and safety personnel time to analyze data captured during lightning strikes near the pad on July 10. Endeavour will deliver the Japanese Experiment Module's Exposed Facility, or JEM-EF, and the Experiment Logistics Module-Exposed Section, or ELM-ES, in the final of three flights dedicated to the assembly of the Japan Aerospace Exploration Agency's Kibo laboratory complex on the International Space Station. STS-127 is the 29th flight for the assembly of the space station. Photo credit: NASA/Kim Shiflett