Workers check the movement of space shuttle Endeavour's Orbiter Boom Sensor System as it is lowered into the payload bay.

In NASA Kennedy Space Center's Orbiter Processing Facility bay 2, workers check the movement of space shuttle Endeavour's Orbiter Boom Sensor System as it is lowered into the payload bay. The OBSS is being reinstalled in the payload bay. The OBSS is a 50-foot boom with a laser and cameras on it that astronauts use to inspect a shuttle's heat shield while in orbit. After returning from the STS-127 mission July 31, 2009, Endeavour now is being processed for the STS-130 mission targeted for Feb. 4, 2010. Endeavour will deliver to the International Space Station the Tranquility pressurized module that will provide room for many of the station's life support systems. Photo credit: NASA/Jack Pfaller