The U.S. space agency has set May 12 as the target launch date for space shuttle Atlantis' mission to repair the Hubble Space Telescope.

The final servicing mission to Hubble was delayed in September when a data-handling unit on the telescope failed. But the National Aeronautics and Space Administration said engineers have since created a spare unit.

The 11-day flight will feature five spacewalks to extend Hubble's life by refurbishing and upgrading the telescope with state-of-the-art science instruments and swapping failed hardware, NASA said.