NASA announced that the Expedition 17 crew members docked their Soyuz TMA-12 with the orbiting laboratory's Pirs Docking Compartment at 8:57 a.m. EDT Thursday, marking the beginning of their six-month stay aboard.

After the hatches opened at 11:40 a.m., the Expedition 17 crew members were welcomed by the Expedition 16 crew, including astronaut Garrett Reisman.

Commander Sergei Volkov and Flight Engineer Oleg Kononenko will begin a six-month stay in space while spaceflight participant So-yeon Yi will return to Earth with Expedition 16 crew members, Commander Peggy Whitson and Flight Engineer Yuri Malenchenko, on April 19

The first South Korean to fly in space and the youngest female astronaut, So-yeon Yi worked for the Korean Institute of Machine-building and Materials during July 2000 to August 2000. From March 2001, she participated in development, manufacturing and testing of hardware in the Center of Nana Technologies of the Korean Science-Technical Institute.

In December 2006, she was selected as an astronaut candidate for the first South Korean space mission. Since that time she has worked as a research fellow in the Department of Korean Astronaut Mission Project of the Korean Aerospace Research Institute. In September 2007, Yi was assigned to train as a spaceflight participant.

During her stay at ISS, So-yeon Yi intends to conduct 18 scientific experiments and has also pledged to cook a Korean meal there. On April 12, she will sing to mark Cosmonauts' Day.

Lt. Col. Sergey Volkov is making his first trip into space as commander of Expedition 17. Selected for training as a test cosmonaut in 1997, he has been training for missions to the International Space Station since 2000. He trained as the backup for Expedition 7 and 13. He also trained for the primary crew of Expedition 11 until the station missions were reorganized following the Columbia accident. He will return to Earth in October.

Before the arrival of the Expedition 17 crew, the ISS crew performed maintenance tasks and organized hardware and materials to be brought back with Whitson and Malenchenko aboard the Soyuz TMA-11 spacecraft on April 19.

Whitson and Malenchenko launched to the station Oct. 10. Flight Engineer Garrett Reisman launched to the station on the STS-123 mission of Endeavour March 11. He joined Expedition 16 in progress and will continue his tour with the Expedition 17 crew.