Mission Specialist Christopher Cassidy finishes suiting up before entering space shuttle Endeavour for the simulated launch countdown.

In the White Room on the orbiter access arm of the fixed service structure on Launch Pad 39A at NASA's Kennedy Space Center in Florida, STS-127 Mission Specialist Christopher Cassidy finishes suiting up before entering space shuttle Endeavour for the simulated launch countdown. The crew is at Kennedy for a launch dress rehearsal called the terminal countdown demonstration test, or TCDT, which includes the simulation, emergency exit training and equipment familiarization. Endeavour's STS-127 mission is the final of three flights dedicated to the assembly of the Japanese Kibo laboratory complex on the International Space Station. Endeavour's launch is scheduled for June 13 at 7:17 a.m. EDT. Photo credit: NASA/Troy Cryder