Endeavour's astronauts get some down time today. After several days of extensive robotics, installation of new hardware and two spacewalks, the crew will have mostly off-duty time.
Meanwhile, three space station crew members prepare to come home.
The shuttle crew and Expedition 27 Flight Engineer Ron Garan woke at 9 p.m. CDT to the song "Times Like These" by the band Foo Fighters for mission specialist Andrew Feustel.
Shortly after they woke up, STS-134 commander Mark Kelly and mission specialist Mike Fincke participated in an educational downlink with Mesa Verde Elementary School in Tucson, Arizona. They spoke with about 400 of the classmates of 9-year-old Christina Taylor-Green, who was killed on Jan. 8 in the assassination attempt against Kelly's wife, Congresswoman Gabrielle Giffords.
"I've come to admire your classmate, Christina Green, very much," said Kelly, who had with him in space the school's yearbook. "I have learned a lot about her."
Later in their day, mission specialist Roberto Vittori will join Expedition 27 flight engineer and fellow Italian astronaut Paolo Nespoli for a special call from Giorgio Napolitano, the President of the Italian Republic.
The Expedition 27 crew woke at 6:31 a.m. to prepare for the departure of three of their crewmates. Dmitry Kondratyev, Nespoli and Cady Coleman are wrapping up their long duration stay and will close the hatches on their Soyuz return craft at 1:21 p.m. and undock from the station at 4:35 p.m. Landing is expected to occur at 9:26 p.m.
At 1:45 p.m. CDT, hatches were closed between the International Space Station (ISS) and Soyuz TMA-20. Expedition 27 crew members Dmitry Kondratyev with Roscosmos, NASA astronaut Cady Coleman and Paolo Nespoli with the European Space Agency are preparing to undock at 4:35 p.m.
After it undocks, the Soyuz will move to between 590 and 650 feet from the station and hold in place while Nespoli takes still photographs and video of the space station. The station will rotate 130 degrees to provide Nespoli with ideal views of the complex with shuttle Endeavour attached.
The deorbit burn targeted for 8:36 p.m. will lead to a landing at 9:26 p.m. in Kazakhstan.
Endeavour's crew were scheduled to retire for the day at 11:26 a.m., but had the choice to stay awake for the Soyuz's undocking, a first when the space shuttle has been there.
"There's no requirement for them to be awake," said space station flight director Derek Hassmann. "They don't play a role at all in the undock. All the Soyuz undock activities are controlled by Moscow."
"If I had to guess, if it was me in that position, I'd be awake for a couple of hours," said Hassmann.
Soyuz TMA-20, carrying three Expedition 27 crewmembers, departed the International Space Station Monday, on its way back to Earth with a brief layover to capture imagery of the orbiting complex and the space shuttle Endeavour attached to it.
The Russian crewed spacecraft undocked from the ISS at 4:35 p.m. CDT beginning its journey home with a landing in Kazakhstan planned for 9:26 p.m. (8:26 a.m. May 24 local time).
Before leaving the vicinity of the station, Roscosmos cosmonaut Dmitry Kondratyev will fly the Soyuz to a distance of between 590 and 650 feet away and pause, allowing European Space Agency (ESA) flight engineer Paolo Nespoli to climb out his seat, enter the spacecraft's orbital module and photograph the orbiting lab with space shuttle Endeavour docked.
This is the first time a Soyuz has departed the station while a shuttle has been present.
Orbiting 650 feet behind the International Space Station, the Earth-bound crew aboard the Soyuz TMA-20 spacecraft paused Monday to look back and capture an unprecedented series of photos of the space station with space shuttle Endeavour attached.
The first-of-its-kind photo op of the orbiting laboratory flying together with the spacecraft that delivered its first and last components came after the Soyuz undocked from the ISS with Expedition 27 crew members Dmitry Kondratyev, Cady Coleman and Paolo Nespoli on board.
Kondratyev, as Soyuz TMA-20's commander, piloted the Russian vehicle while Nespoli climbed into the spacecraft's habitat module and took both still photos and video of the shuttle-station complex as it rotated to offer a better view of Endeavour.
Once on the ground, the Soyuz crew will hand off the camera cards used to record the historic photos to NASA, which will process and release the photos to the public no earlier than Tuesday afternoon.
Soyuz TMA-20 is scheduled to land on the steppe of Kazakhstan at 9:26 p.m. CDT, 159 days after launching to the space station.