Williams, the International Space Station's Expedition 22 commander, and Suraev, the mission's flight engineer, landed their Soyuz TMA-16 spacecraft on the steppes of Kazakhstan at 7:24 a.m. EDT. The spacecraft had undocked from the ISS at 4:03 a.m.
NASA said Williams and Suraev were launched aboard the Soyuz TMA-16 spacecraft Sept. 30 from the Baikonur Cosmodrome in Kazakhstan. They spent 167 days at the orbiting station, presiding over the completion of the complex's U.S. segment.
NASA said Williams has now logged 362 total days in space, placing him fourth on the all-time U.S. list of long-duration space travelers. Peggy Whitson, who has spent 377 days in space, tops that list.
The space station is currently staffed by Expedition 23 Commander Oleg Kotov and astronauts Soichi Noguchi and T.J. Creamer. The space agency said three other astronauts -- Alexander Skvortsov, Tracy Caldwell Dyson and Mikhail Kornienko -- will lift off April 2 from the Baikonour Cosmodrome and join the current station crew with an April 4 docking.