Three crew members from the International Space Station, including South Korea's first astronaut, have arrived safely back on Earth, albeit 20 minutes late and 420 kilometres off target. Rescue helicopters raced to the site west of the scheduled landing zone in Kazakhstan, where medical staff checked Yi So-Yeon, Russian flight-engineer Yuri Malenchenko and the US Commander Peggy Whitson.

Officials say that after leaving the International Space Station, the Soyuz capsule embarked on what they called a "ballistic re-entry" - an uncontrollable, steep trajectory, much shorter than the planned path home. Mission Control had a nervous wait after touchdown - a ballistic re-entry subjects astronauts to severe gravitational forces, up to ten times those experienced on earth.

Officials say the crew had not reported their severe re-entry course, and the incident will be investigated. The Soyuz craft, which is the world's longest serving space capsule, landed near the Kazakh border, south-east of the Russian city of Orsk.