Identical twin astronauts Scott and Mark Kelly subjects of scientific study
When one is on the space station, the other will be undergoing medical tests while on the ground
Astronauts Scott and Mark Kelly will take part in an unprecedented study of identical twins to better understand the effects of prolonged weightlessness by comparing the twin in space with the twin on the ground.
When Scott Kelly embarks on a one-year space station stint next spring, his twin brother and retired astronaut Mark Kelly will be joining in from earth, undergoing medical testing before, during and after his brother's American-record-setting flight.
Mark Kelly draws the line, though, at mimicking his brother's extreme exercise in orbit or eating "crappy space station food". The twins are aged 50.
Scott Kelly has volunteered to spend an entire year aboard the International Space Station beginning next March, along with Russian cosmonaut Mikhail Kornienko, 54, a former paratrooper.
No American has come close to a year; seven months is the maximum for a single human mission that Nasa, the US space agency, allows. The Russians, on the other hand, are old hands at long-duration spaceflight, claiming title to a record-setting 141/2- month mission back in 1994-95.
"No second thoughts. I'm actually getting kind of excited about the whole idea as we get closer," Scott said in a recent interview.