Scott Kelly and crewmates bid goodbye to space station

In the final hours of a 340-day mission, Scott Kelly and Mikhail Kornienko said goodbye to their crewmates and closed the hatch to the International Space Station on Tuesday, heading for a parachute-assisted touchdown in Kazakhstan a few hours later.

They will be joined by veteran Russian cosmonaut Sergey Volkov, who has spent the last six months on the space station and will command the Soyuz TMA-18M crew capsule during descent.

Email the author.

Follow Stephen Clark on Twitter: @StephenClark1.