Astronaut Christina Koch will spend nearly a year aboard the International Space Station, NASA announced on Wednesday, with her return trip delayed to February 2020. During her 11 months in space, she will monitor how her body responds to the mission, producing much-needed data about how well human bodies can withstand the dangers and hardships of long-term spaceflight. So far, that data has been difficult to come by. Standard space station missions last about six and a half months, and only a handful of NASA astronauts have stayed in orbit longer than 200 days in a single spaceflight. That's problematic...