Standby rescue space shuttle rolled to launch pad

The shuttle is being prepared alongside its sister ship, Atlantis, which is scheduled to lift off May 12 on a final mission to refurbish the Hubble Space Telescope.

NASA wants to have a rescue team ready to fly home the Atlantis' crew, who would be unable to seek refuge in the International Space Station in an emergency. The Endeavour is the lifeboat.

"They are essentially processing the vehicle as if it's going to launch and then it's going to sit there on the launch pad in a state of readiness," NASA spokesman Kyle Herring said.

NASA initially canceled its final servicing call to Hubble after the 2003 Columbia disaster, saying it could not risk losing another shuttle crew due to damage from launch debris.