This undated photo provided by NASA, astronauts Mark Kelly, right, STS-124 commander, and Scott Kelly are pictured in the check-out facility at Ellington Field near NASA's Johnson Space Center in Houston. NASA announced Friday, March 7, 2014, that Mark Kelly and astronaut Scott Kelly will participate in 10 different investigations. Craig Kundrot, deputy chief scientist of NASA's Human Research Program, says in a news release that the brothers provide a unique opportunity to study two people with the same genetics who were in different environments. Officials say Scott Kelly spent a year in space while Mark Kelly was on Earth. NASA says it is hoping the studies can be the basis for future research initiatives. (AP Photo/NASA)
