Astronaut Scott Kelly is to launch into space today to begin a year living on the International Space Station while his twin brother Mark Kelly, a former astronaut, will remain earthbound, Discover's D-brief blog says. Most stays at the space station are six months in length; this is the first yearlong stay.
As part of the Twins Study, NASA will sequence the Kelly twins' genomes and monitor their health — everything from their gut bacteria to their eyesight and telomere length — to try to distinguish the effects of life in space from genetic effects, NPR and Nature News say.
"The advantage of this study is that we will get a complete profile, I would even argue the most comprehensive molecular profile of a human being that's maybe ever been generated," Weill Cornell Medical College's Christopher Mason, who is working on the Twins Study, tells NPR. "And then, to boot, we'll get the comparison of someone on Earth who's the identical twin."
However, his colleague Francine Garrett-Bakelman cautions that with only one set of twins, definitive conclusions can't really be made, though "you can get some idea of what things might change over time, between space and Earth."
And that, NPR adds, is what NASA needs to know about before embarking on longer flights in space, such as to Mars.
The study wasn't part of NASA's original plan for this lengthy space stay, NPR notes, but came about as Scott Kelly was preparing for a press conference and wanted to know how to answer questions about a comparative study between him and his brother, if asked.
Nature News notes that the results from the study may never be published if they reveal sensitive medical information about the brothers.