A thermal protection system technician prepares the surface under space shuttle Atlantis before installing a heat shield tile.

In Orbiter Processing Facility-1 at NASA's Kennedy Space Center in Florida, a thermal protection system technician prepares the surface under space shuttle Atlantis before installing a heat shield tile. The tiles are part of the Orbiter Thermal Protection System, thermal shields to protect against temperatures as high as 3,000 degrees Fahrenheit, which are produced during descent for landing.

Atlantis is being prepared for the STS-135 mission, which will deliver the Raffaello multi-purpose logistics module packed with supplies, logistics and spare parts to the International Space Station. STS-135 is targeted to launch June 28, and will be the last spaceflight for the Space Shuttle Program. Photo credit: NASA/Jack Pfaller