NASA will be sending an identical twin into space in order to better study the effects of an extended space flight on a human being.
In 1905, Albert Einstein presented the twin paradox as part of his work on special relativity: if an identical twin travels to space in a high-speed rocket, he'll return to find that his brother - who remained on Earth - will have aged more. In a new study, NASA is looking to test just what changes an astronaut undergoes during an extended space journey - by sending an identical twin into space.
Scott Kelly's one year mission to the International Space Station is set to kick off in March 2015. His identical twin brother, retired astronaut Mark Kelly, will remain on Earth as the control. Once these genetically identical individuals will be reunited, tests will determine just how identical they still are.
Samples and measurements from the brothers will be taken before, during, and after the space flight, and they will be compared with respect to genetics, biochemistry, vision, cognition, and much more. Tests will seek to determine how the human immune system is affected in space, whether space radiation is prematurely aging astronauts, and why eyeglasses sometimes don't work in space. These investigations are the first of their kind, and NASA is breaking new ground in studying how genetically identical twins may be changed by space flight.