A new crew is taking over the International Space Station after two NASA astronauts and one Russian cosmonaut successfully returned to Earth Monday night.
After undocking from the space station, Expedition 35 Commander Chris Hadfield and Flight Engineer Tom Marshburn and Cosmonaut Roman Romanenko landed their Soyuz TMA-07M spacecraft in southern Kazakhstan at 10:31 p.m.
The Soyuz spacecraft carrying the astronauts launched from Kazakhstan in December. The three men spent 144 days aboard the International Space Station.
Hadfield, a prolific tweeter, will be missed by his nearly 900,000 social network followers. Over the weekend, he tweeted, "Good morning, Earth! We're supposed to be sleeping late to be rested for tonight's Soyuz flight home, but I'm finding it hard to sleep in."
Once Hadfield was on the space capsule for his ride home, his son, Evan, took over tweeting about his father's return flight.
"Wonder what it looks like in the Soyuz capsule? I think the term they prefer is "cozy," he tweeted, adding this photo.
He later tweeted, "Under 15 minutes to touchdown. Roman Romanenko, the Soyuz Commander, could not be doing a better job returning our crew home," and welcomed his father home by tweeting, "I love you Dad. Welcome back to Earth."
Marshburn, a tweeter with nearly 40,000 followers, ended his time on the space station by tweeting, "Leaving is bittersweet. It's been an unbelievable ride. Can't wait to see what's next!"
The astronauts' leaving the station on Monday marked the end of Expedition 35 and the beginning of Expedition 36 under the command of Russian cosmonaut Pavel Vinogradov, who is to remain on the station with Flight Engineers Chris Cassidy and Alexander Misurkin until September.
Vinogradov, Cassidy and Misurkin arrived at the station aboard the Soyuz TMA-08M spacecraft in March. Three more crew members, Expedition 36 Flight Engineers Karen Nyberg, Fyodor Yurchikhin and Luca Parmitano, are due to join them on May 28.
One of Marshburn's final tasks on the orbiter was a five-and-a-half-hour spacewalk with Cassidy on Saturday to repair an ammonia leak on a coolant loop on the space station's backbone.
The two astronauts removed a 260-pound pump controller box from the backbone and replaced it with a spare that had been stowed nearby on the port-side of the backbone of the station. NASA reported that Mission Control ran the new pump while the spacewalkers watched for any ammonia leakage, which shows up looking like snowflakes.
The space agency reported that there has been no sign of a new leak but it will continue to be monitored.
Ammonia, a colorless gas made up of nitrogen and hydrogen, is used to cool the space station's power channels, which provide electricity to different systems. Each solar array, for instance, has its own independent cooling loop.
The leak was first reported last Thursday when astronauts noticed small, white flakes floating away from the back of the space station. The problem appears to be in the same area where a leak was detected last fall. On Nov. 1, astronauts did a spacewalk to fix that problem.
Sharon Gaudin covers the Internet and Web 2.0, emerging technologies, and desktop and laptop chips for Computerworld. Follow Sharon on Twitter at @sgaudin, on Google+, or subscribe to Sharon's RSS feed . Her email address is firstname.lastname@example.org.