NASA gears up to study twin astronauts

NASA has a rare opportunity ahead. Astronaut Scott Kelly is scheduled to spend an entire year on the International Space Station starting in March 2015. Meanwhile, back on Earth, his twin brother Mark Kelly will go about his usual life in Arizona.

Mark commanded the final mission of the space shuttle Endeavor in 2011. His wife, former Congress member Gabrielle Giffords, was severely injured in a shooting in Tucson, Ariz., in January 2011. Mark retired from NASA in late 2011 to be with his wife during her extended recovery and spend more time with his family.

Scott will be busy setting a record for the longest space mission by a NASA astronaut, but there will still be time to conduct some investigations into how the twins' bodies react in their very different environments.

The research plans came about at the suggestion of the twins. "This is a once-in-a-space-program opportunity," said John Charles, chief of NASA's Human Research Program's International Science Office.

NASA is soliciting ideas for ways to test the twins with a call for proposals titled "Differential Effects on Homozygous Twin Astronauts Associated with Differences in Exposure to Spaceflight Factors."

Initial plans include collecting blood samples. Any other tests designed for the twins must not interfere with Scott's duties while on the ISS. "Proposed investigations should focus on the analysis of human molecular responses to the physical, physiological, and environmental stressors associated with human spaceflight," says a NASA release.

Studying the differences in the Kelly twins during an entire year in space could help NASA gain a deeper understanding of how spaceflight impacts the body, and work toward finding ways to reduce risks to humans in space.

Proposals are due by September 17, so there's still time for researchers to get in on this rare twin study.