Members of the crew look at the trailing umbilical system reel assembly that will be installed on the International Space Station.

Members of the crew for mission STS-121 look at the trailing umbilical system reel assembly that will be installed on the International Space Station during the mission. Seen here are Mission Specialists Stephanie Wilson and Lisa Nowak (background) and Michael Fossum (center front). The crew is taking part in a Crew Equipment Interface Test (CEIT) inside the Space Station Processing Facility at NASA's Kennedy Space Center. A CEIT provides hands-on experiences with equipment used on-orbit. Mission STS-121 is the second in the Return to Flight sequence and will carry on improvements that debuted during last year's STS-114 mission and build upon those tests. Launch is scheduled in July. Photo credit: NASA/Kim Shiflett