Mission Specialist Lisa Nowak is helped with her boot during suitup for a second launch attempt on Space Shuttle Discovery.

STS-121 Mission Specialist Lisa Nowak is helped with her boot during suitup for a second launch attempt on Space Shuttle Discovery. The first launch attempt July 1 was scrubbed due to weather concerns and postponed 24 hours. The launch of Space Shuttle Discovery on mission STS-121 is the 115th shuttle flight and the 18th U.S. flight to the International Space Station. During the 12-day mission, the STS-121 crew will test new equipment and procedures to improve shuttle safety, as well as deliver supplies and make repairs to the International Space Station. Photo credit: NASA/Kim Shiflett