Stock Photo - San Ko (center) and So-yeon Yi (left), South Korean prime and backup spaceflight participants, respectively, participate in a space station hardware training session in the Space Vehicle Mockup Facility at the Johnson Space Center. San is scheduled to launch with the Expedition 17 crew on the Soyuz TMA-12 spacecraft April 8 from the Baikonur Cosmodrome under a commercial agreement between the South Korean government and Roscosmos for nine days on the International Space Station; San is scheduled to return to Earth April 19 with the Expedition 16 crew. United Space Alliance (USA) instructor Glenn Johnson assisted the spaceflight participants. [So-yeon Yi has been named to replace San Ko as South Korea's first astronaut, it was announced March 10.]