NASA’s Liberty Star brought back one of two solid rocket boosters (SRBs) from Space Shuttle Atlantis Sunday.
The solid rocket boosters would normally be reprocessed and relaunched on future shuttle flights. Although there will not be another shuttle flight after this one, these boosters may be used in an upcoming heavy lift rocket that NASA plans to announce next month.
Watch Liberty Star return to Port Canaveral:

Liberty Star and her sister ship Freedom Star are sent out ahead into the Atlantic Ocean ahead of a Shuttle launch and are on station at the time of launch near the projected area the boosters hit the ocean. The rocket boosters typically hit the ocean 160 miles from the launch pad.
Freedom Star is expected to return today with the second booster.
Click here to read a fact sheet from NASA on the recovery operations.