The crew of six left the International Space Station, pausing just long enough Monday to perform a victory lap and test equipment for a future interplanetary ship. NASA's youngest shuttle- the baby of the fleet with just 25 space voyages- is due back in Florida early Wednesday.
Monday, Commander Mark Kelly received a special wakeup call- a song chosen by his wife, Congresswoman Gabrielle Giffords. The song was called "Slowness" from the Tucson, Ariz., band Calexico.
The song holds a special meaning for Kelly and Giffords, who is recovering from a gunshot wound to her head.
"It's about two people on a trip reaching across the distance," said Kelly. "And it references places like Signal Hill, and Gate's Pass and Tucson. I know she really, really wants to get back there and is really looking forward to that. So it's an appropriate song because that's coming soon."
Giffords will not be attending Wednesday's landing because she's recovering from skull reconstruction surgery.
The spacecraft had an unusual beginning.
After the tragic 1986 explosion that destroyed the Challenger, NASA needed another shuttle. Endeavour was built in Palmdale, Calif., from a collection of spare parts.
It went on its first mission in 1992 sent to rescue a communications satellite stranded in orbit. In a history-making spacewalk, three astronauts grabbed the huge satellite by hand.
What may be Endeavour's most impressive space feat came in December of 1993.
The shuttle flew into high orbit to repair the Hubble Space Telescope.
As the world watched, seven astronauts outfitted the telescope with equipment to restore its vision during five spacewalks. Without the repair job, the Hubble would have been left permanently out of focus.
The shuttle was often called on for important scientific missions, including the assembly of the first International Space Station.
On this final mission, Kelly and his crew completed the U.S. portion of the space station. They also installed a $2 billion device that could determine how our universe was formed.
Endeavor's next and final stop will be at the Los Angeles California Science Center. Built to replace the lost Challenger, Endeavour will have racked up 123 million miles by flight's end, beginning with its first journey in 1992, and have circled Earth more than 4,670 times.
The NASA space shuttle Atlantis will make one last supply run to the space station this summer to close out the 30-year shuttle program.
The Associated Press contributed to this story