In the Space Station Processing Facility at NASA Kennedy Space Center take part in the crew equipment interface test.

In the Space Station Processing Facility at NASA Kennedy Space Center, members of the STS-121 crew take part in the crew equipment interface test (CEIT). Seen here is Mission Specialist Michael Fossum, looking at the replacement trailing umbilical system reel assembly that will be installed on the International Space Station. The 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 May. Photo credit: NASA/Kim Shiflett