If humans ever leave this solar system, they probably won't do it aimlessly. More likely they'll set a course for some distant waypoint, perhaps another solar system, to visit, study, or maybe even settle. And when they do, there's a good chance the destination they choose will have been discovered by NASA's new planet-hunting spacecraft. Called the Transiting Exoplanet Survey Satellite, the instrument will soon hitch a ride to space aboard one of SpaceX's Falcon 9 rockets.