APE CANAVERAL, Fla. (AP) -- The astronauts on NASA's final shuttle voyage floated out of the International Space Station for the last time Monday, leaving behind a historic U.S. flag and a commemorative shuttle model to mark the end of a 30-year era.
Atlantis was set to undock from the orbiting lab early Tuesday -- providing the last glimpses of a space shuttle in flight before the fleet is retired.
As the hatches swung shut behind the four crew members of Atlantis, it closed "a chapter in the history of our nation," space station astronaut Ronald Garan Jr. noted in Monday's emotional farewell ceremony.
Atlantis is due to land at Florida's Kennedy Space Center just before sunrise Thursday. (18 images)
This panoramic view was photographed from the International Space Station, looking past the docked space shuttle Atlantis' cargo bay and part of the station including a solar array panel toward Earth, was taken on July 14, 2011 as the joint complex passed over the southern hemisphere. Aurora Australis or the Southern Lights can be seen on Earth's horizon and a number of stars are visible also. NASA
This panoramic view provided by NASA was photographed from the International Space Station, looking past the docked space shuttle Atlantis' cargo bay and part of the station including a solar array panel toward Earth, was taken on July 14, 2011 as the joint complex passed over the southern hemisphere. Aurora Australis or the Southern Lights can be seen on Earth's horizon and a number of stars are visible also. NASA
This image provided by NASA was photographed during a July 12 spacewalk and shows the International Space Station's Cupola, backdropped against black space, a horizon scene and various components of the orbiting outpost, including the Leonardo Permanent Multipurpose Module, right, along with two "parked" Russian spacecraft -- a Soyuz and a progress supply ship. Node 3 or Tranquility (on which the Cupola is mounted) is just out of frame, bottom. NASA
With his feet secured on a restraint on the space station remote manipulator system's robotic arm or Canadarm2, NASA astronaut Ron Garan, Expedition 28 flight engineer, carries the pump module, which was the focus of one of the primary chores accomplished on a six and a half hour spacewalk on Tuesday, July 12, 2011. NASA astronaut Mike Fossum, also a station flight engineer, who shared the spacewalk with Garan, is out of frame. NASA
In this Tuesday, July 12, 2011 photo made available by NASA, astronaut Ron Garan rides on the International Space Station's robotic arm as he transfers a failed pump module to the cargo bay of space shuttle Atlantis. Garan and fellow Expedition 28 astronaut Mike Fossum's over six-hour spacewalk performing upgrades and maintenance on the orbiting outpost was the final scheduled spacewalk during the final shuttle mission. NASA
This close-up image shows the 'Materials on International Space Station Experiment-8.' Taken during the spacewalk on July 12, 2011, the small circles pictured are test beds for materials and computing elements attached to the outside of the International Space Station. These elements are being evaluated for the effects of atomic oxygen, ultraviolet, direct sunlight, radiation, and the extremes of heat and cold. Researchers hope the results will provide a better understanding of the durability of various materials and computing elements when they are exposed to the rigors of space environments and hope to incorporate what is learned into the design of future spacecraft. NASA
In this image provided by NASA the Great Salt Lake in Utah serves as a striking visual marker for the STS-135 astronauts orbiting over North America in the space shuttle Atlantis Saturday July 9, 2011. A sharp line across the lake's center is caused by the restriction in water flow from the railroad causeway. The eye-catching colors of the lake stem from the fact that Great Salt Lake is hypersaline, typically 3-5 times saltier than the ocean. NASA
The "Tongue of the Ocean" and several of the 2700 islands in the Bahamas chain and part of peninsular Florida, at right, including Cape Canaveral, the location of the Kennedy Space Center, are easily recognized in this scene photographed by one of the STS-135 crewmembers while Atlantis was docked with the International Space Station Tuesday July 12, 2011. NASA
Mission specialist Sandy Magnus floats between stacks of supplies and equipment in the Raffaello multi-purpose logistics module aboard the International Space Station on Monday, July 11, 2011. The supplies and spare parts are for use and consumption for the ISS and its crews. Raffaello was transported up to the station by the space shuttle Atlantis. NASA
The docking mechanism in space shuttle Atlantis' payload bay shortly before the shuttle docked with the International Space Station on Sunday, July 10, 2011. The orbiter boom sensor system and a portion of the remote manipulator system's robot arm are visible in the frame, exposed during a busy third day in space for the astronauts. NASA
Astronaut Ron Garan took this image during the spacewalk conducted on Tuesday, July 12, 2011. It shows the International Space Station with Space Shuttle Atlantis docked on the right and a Russian Soyuz on the far left. In the foreground is the Alpha Magnetic Spectrometer (AMS) experiment installed during the STS-134 mission. AMS is a state-of-the-art particle physics detector designed to use the unique environment of space to advance knowledge of the universe and lead to the understanding of the universe's origin by searching for antimatter and dark matter, and measuring cosmic rays. NASA
Space shuttle Atlantis and its payload is shown while in orbit Sunday, July 10, 2011. Seen at the rear of the cargo bay is the Raffaello multi-purpose logistics module, packed with supplies and spare parts for the International Space Station. Atlantis is delivering more than 4 tons of food, clothes and other space station provisions -- an entire year's worth, in fact, to keep the complex going in the looming post-shuttle era. Atlantis' journey marks the final shuttle mission by NASA. NASA
The space shuttle Atlantis is seen over the Bahamas prior to docking with the International Space Station on Sunday, July 10, 2011. Part of a Russian Progress spacecraft which is docked to the station is in the foreground. NASA
Backdropped by a mostly blue Earth scene, part of the Raffaello multi-purpose logistics module, the stabilizer of space shuttle Atlantis and the orbital maneuvering system pods are seen in this view photographed by one of the STS-135 crew members using windows on the spacecraft's aft flight deck during the mission's second day of activities in Earth orbit. NASA
Parts of Atlantis' main engines are visible in this image, which is one of a series of images taken during the back flip or rendezvous pitch maneuver (RPM). Atlantis 'posed' for this and other photographs and visual surveys on approach to the International Space Station. The station crew used an 800 millimeter lens to capture this particular series of images. NASA
This is one of a series of images taken by the station crew of space shuttle Atlantis in Earth orbit. Seen at the rear of the cargo bay is the Raffaello multi-purpose logistics module, packed with supplies and spare parts for the orbiting outpost. The shuttle 'posed' for photographs and visual surveys and performed a back-flip for the rendezvous pitch maneuver. A 400 millimeter lens was used to capture this particular series of images.
Image Credit: NASA NASA
Space shuttle Atlantis' external fuel tank is seen after its release following the successful launch of the STS-135 mission. One of Atlantis' crew members using a hand-held still camera exposed the image. NASA
Space shuttle Atlantis is seen through the window of a Shuttle Training Aircraft as it lifts off from the Kennedy Space Center Friday, July 8, 2011, in Cape Canaveral, Fla. Atlantis is the 135th and final space shuttle launch for NASA. NASA / Dick Clark