Space shuttle Discovery undocked from the International Space Station (ISS) Saturday morning, 10 days after arriving to deliver more than seven tons of supplies and equipment to the orbiting laboratory.
"We hope we didn't tear up your house too much," Discovery commander Alan Poindexter told his station counterpart, Russian cosmonaut Oleg Kotov, during a farewell ceremony. "We tried to a good job of cleaning when we left [but] if we leave anything behind, you can bring it with you home."
"Thank you very much," said Kotov. "We're really grateful for your help and your job you did for us."
Shuttle pilot Jim Dutton backed the orbiter away at 8:52 a.m. EDT (1252 GMT), before beginning a 360-degree fly-around of the station allowing his six crewmates to take photos and video of the outpost's exterior condition.
"Dex, you and your crew were excellent guests, we loved having you here," station flight engineer Timothy "T.J." Creamer told Poindexter. "You helped us leave the station in a better place then when you got here. Come back soon."
Poindexter said his crew loved every minute of it.
"Safe landing," Creamer replied. Discovery is due to land Monday morning in Florida.
Final separation for the two spacecraft was expected at 10:35 a.m. EDT (1452).
A failed antenna system aboard Discovery, which is usually relied upon to provide radar data during docking and undocking did not affect the shuttle's departure.
"For the most part, it's ops nominal," said lead shuttle flight director Richard Jones on Friday. "It was a pretty ops nominal day for docking. We're going to make it look pretty much the same for undocking as well."
The Ku-Band antenna, which the astronauts discovered was not working soon after reaching orbit 12 days ago, is also used to transmit live video to Mission Control. Without it, those watching from the ground will need to wait until Discovery lands to see all but still shots of what the crew saw during undocking.
"We're going to be absent the ability to see onboard video because of the [failed] Ku system," explained Jones. "We're going to have what we call SSV or sequential still video, where we're going to have intermittent still shots of whatever view the crew is downlinking to us."
Discovery launched on April 5 on what is now a 14-day mission to deliver supplies and equipment to the International Space Station.
During their time docked at the space station, the STS-131 astronauts transferred 7.6 tons of experiments and supplies to the station, most of which was carried to orbit inside the Leonardo multi-purpose logistics module (MPLM). The cargo module, now back inside Discovery's payload bay, is returning 2.5 tons of science results and trash to Earth.
This will be the last round-trip for Leonardo to and from orbit. On its flight, the module will be left at the station to serve as a closet and storage space for the crew.
In addition to breaking up the record-tying 13-member joint crew, Discovery's seven astronauts' departure also marked the division of the largest group of women and largest group of Japanese astronauts aboard one spacecraft, at four and two respectively.
Stephanie Wilson, Dorothy Metcalf-Lindenburger and Japan Aerospace Exploration Agency (JAXA) astronaut Naoko Yamazaki are returning to Earth on the shuttle, leaving Tracy Caldwell and Soichi Noguchi among the crew still on the station.
Also onboard Discovery are spacewalkers Rick Mastracchio and Clayton Anderson, as well as Poindexter and Dutton.
This mission is Discovery's second-to-last spaceflight and one of NASA's final few shuttle flights before the space plane fleet is retired later this year. NASA plans to launch only three more missions after this one. The final flight, set for September, will also be on Discovery and include the Leonardo cargo pod, though the module will be permanently left at the space station as a storage room.
During their final scheduled full day in space, Discovery's crew will test the flight control systems that will allow them to convert the orbiter from a spacecraft to a glider for the journey back to Earth.
Discovery's first landing opportunity at NASA's Kennedy Space Center in Florida is at 8:48 a.m. (1248 GMT) on Monday.