United Space Alliance technicians mark the progress of space shuttle Discovery as it is lowered onto the mobile launcher platform.

In high bay 3 of the Vehicle Assembly Building at NASA's Kennedy Space Center, United Space Alliance technicians mark the progress of space shuttle Discovery as it is lowered onto the mobile launcher platform. Discovery will be mated with the solid rocket boosters and external tank already stacked there in preparation for the launch on the upcoming STS-124 mission to the International Space Station. On the mission, the STS-124 crew will transport the Japanese Experiment Module - Pressurized Module and the Japanese Remote Manipulator System to the space station. Launch of Discovery is targeted for May 31 Photo credit: NASA/Jim Grossmann