WASHINGTON — From his eyes to his immune system, astronaut Scott Kelly's body sometimes reacted strangely to nearly a year in orbit, at least compared to his Earth-bound identical twin — but newly published research shows nothing that would cancel even longer space treks, like to Mars.
NASA twins study explores space, the final genetic frontier
Kelly brothers focus of research
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![nasa.jpg](https://statesboroherald.cdn-anvilcms.net/media/images/2019/04/11/images/nasa.max-752x423.jpg)
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