Pilot Alan Poindexter gently backed the shuttle away from the station after the vehicle sprung loose from its docking port, ending a nearly nine-day visit to deliver, install and activate Europe's new orbital laboratory.
He then began guiding the ship through a full lap around the orbiting outpost, primarily so crew members could take pictures of the station's new configuration.
Just before Atlantis undocked, shuttle commander Stephen Frick thanked station commander Peggy Whitson and her crew for their hospitality.
Later, the crew plans to take another close-up laser survey of Atlantis' wings, this time to check for any possible micrometeorite damage that may have occurred in orbit.
Inspections conducted earlier in the mission found a torn corner on a thermal blanket near the shuttle's tail, but engineers are confident it will stand up to the intense re-entry heat.
