Astronaut’s record orbit concludes with safe return

Astronaut Scott Kelly spent 340 days -- the longest an American has ever been in space -- on the International Space Station before descending into Kazakhstan by capsule Tuesday evening. Kelly’s extraterrestrial sojourn was part of a study on the long-term effects of space on the human mind and body. NASA plans to put astronauts on the two-and-a-half year trip to Mars within two decades.