The shuttle Discovery wrapped up a ten day visit to her port-of-call this morning with a departure and ceremonial clang of the brass bell announcing that she has departed the International Space Station.
Discovery undocked from the complex at 8:52 am EDT, this morning with pilot James Dutton at the control stick on the aft flight deck slowly guided the ship out onto the vast ocean of space.
The station-shuttle complex were 217 miles high over New Guinea and crossing northeastward out over the western Pacific Ocean at the time of undocking.
By 9:08 am, the shuttle was 200-feet away from the complex.
The shuttle then moved to a distance of 410-feet from the station. Dutton then began a 360-degree fly around of the orbital complex so that astronauts could photograph the station for engineers on the ground.
The ship's crew also shot close-up photographs of the newly installed ammonia tank assembly located on the starboard one truss.
Discovery docked to the space station on April 7 and went to work docking a module full of supplies, equipment, a crew quarters and more; and performed three spacewalks to install the new ammonia tank.
However, the new tank is not operation due to a faulty nitrogen valve which helps flow the ammonia from the tank and through lines to help cool the station's avionics systems.
Mission control near Houston are still looking at options in either replacing the valve assembly or the entire tank all together.
One option discussed would have station astronaut Tracy Caldwell Dyson spacewalk out with another crew member and replace the valve in a few weeks. Mission managers have stated that adding the valve replacement task to the next shuttle flight STS-132 in May would not happen. That flight has a packed mission of spacewalks already without room in their time line to add the repair job.
The space station's Expedition 23 crew gave a brief farewell ceremony for their departing visitors who arrived at the complex with nearly 17,000 pounds of supplies in the Leonardo module and the ships middeck.
This flight also marked the final time in which a shuttle will be able to carry back to earth a huge amount of the station's trash, experiments, and old equipment -- all stored in Leonardo.
Discovery's hatch was closed at 6:30 am, and pressure sealed for undocking; meanwhile, the station's hatch was closed twenty minutes later.
This week will mark the first time in which two winged spacecraft will fly in space, as the Air Force's X37-V craft prepares for it's Wednesday launch from Cape Canaveral.
The shuttle is scheduled to return home to the Kennedy Space Center on Monday morning at 8:51 am, after spending two full weeks in space.