Three of the International Space Station's crew members have returned safely to Earth, ending their six-month orbital mission.
A Russian Soyuz capsule carrying NASA astronaut Rick Mastracchio, Japanese spaceflier Koichi Wakata and Russian cosmonaut Mikhail Tyurin landed on the steppes of Kazakhstan at 9:58 p.m. ET Tuesday (7:58 a.m. local time Wednesday).
The Soyuz undocked from the space station three and a half hours earlier, while the two vehicles were above Mongolia. The trio's departure marked the end of Expedition 39 and the beginning of Expedition 40 aboard the orbiting lab. [Photos: Expedition 39 in Orbit]
"What an exciting time we shared in this increment," Wakata, Expedition 39's commander, said on Monday as he handed the station's reins over to NASA astronaut Steve Swanson. "Congratulations, and best wishes to the crew of Expedition 40 for a successful mission."
Wakata, Mastracchio and Tyurin enjoyed an eventful and historic stint in orbit after arriving at the space station on Nov. 7, 2013. Wakata became the first Japanese citizen ever to command the station when he took charge of Expedition 39 on March 10.
Expedition 39 also oversaw the arrival of SpaceX's robotic Dragon capsule, which launched toward the space station April 18 on the California-based company's third contracted cargo mission for NASA. (SpaceX holds a $1.6 billion deal to make 12 such flights for the agency.)
Wakata, Mastracchio and Tyurin zipped around Earth 3,000 times during their 188 days in space, traveling more than 78 million miles (127 million kilometers), NASA officials said.
Expedition 40 will start with a skeleton crew that includes Swanson as well as Russian cosmonauts Alexander Skvortsov and Oleg Artemyev. But the space station will soon be up to full strength once again. Three new crew members — NASA's Reid Wiseman, Russia's Max Suraev and Germany's Alexander Gerst — are slated to blast off from Baikonur Cosmodrome in Kazakhstan on May 28.