The Kelly brothers occupy a unique niche in American history—they’re the only blood relatives to ever orbit in space. They’ll achieve an ever greater milestone in February when they meet up at the International Space Station, where Scott will be the station commander and Mark will join him with supplies. Born and raised in a New Jersey suburb, the twins have always followed a similar path: They co-captained their high-school swim team, and each went on to pilot planes during Operation Desert Storm.