The U.S. space shuttle Atlantis undocked from the International Space Station (ISS) at 10:42 a.m. EDT (1442 GMT) Tuesday, wrapping up a 10-day joint operation, according to NASA TV.
"Houston (Mission Control Center) and ISS, Atlantis, confirmed physical separation," shuttle commander Frederick Sturckow reported.
When the scheduled undocking occurred, both spacecraft flew over the Coral Sea northeast of Australia. As a tradition, space station commander Fyodor Yurchikhin rang a bell and said "Atlantis departing."
After Pilot Lee Archambault backs the orbiter 450 feet (about 137 meters) from the the station, he will perform a full fly-around to allow crew members to collect video and imagery of the station and its newly expanded solar wings.
He will perform the final separation engine burn at 12:25 p.m. EDT (1625 GMT) to begin the trip home.
Later in the day, the crew will use the shuttle robot arm and the 50-foot (15 meters) long Orbiter Boom Sensor System to conduct a late inspection of the thermal protection system.
Atlantis reached the station on June 10. The mission, designated STS-117, continued the on-orbit construction of the station with the installation of the new S3/S4 truss segment.
The crew installed the truss on June 11 and conducted four spacewalks to activate the S3/S4 and assisted in the retraction of a set of old solar arrays.
During the third spacewalk, the crew repaired an out-of-position thermal blanket on the left orbital maneuvering system pod.
Atlantis also delivered a new station crew member, Flight Engineer Clayton Anderson. He replaced astronaut Sunita Williams, who is the new woman record holder of the longest-duration single spaceflight.
"There were a lot of things to overcome, but despite those surprises, we managed to do what we always do and meet our mission objectives," NASA flight director Holly Ridings said on Tuesday.
The crew will spend Wednesday preparing for landing. Atlantis' first landing opportunity is at 1:54 p.m. (1754 GMT) Thursday at the Kennedy Space Center in Florida, ending NASA's first shuttle flight this year.
