STS-121 Mission Specialists Lisa Nowak inspect cables in the mid-body of Space Shuttle Discovery on Launch Pad 39B.

STS-121 Mission Specialists Lisa Nowak (left, above) and Piers Sellers (right, below) inspect cables in the mid-body of Space Shuttle Discovery on Launch Pad 39B. On the 12-day mission, the crew will test new equipment and procedures to improve shuttle safety, as well as deliver supplies and make repairs to the station. This mission is the 115th shuttle flight and the 18th U.S. flight to the station. Photo credit: NASA/Kim Shiflet