A SpaceX Falcon Heavy rocket will launch NASA’s Europa Clipper to begin its journey to the Galilean moon of the same name. Europa, a moon believed to have a saltwater ocean on its surface, is the fourth largest of Jupiter’s 95 moons. It’s also the sixth closest to the planet. This Falcon Heavy rocket will be flown in a fully expendable configuration, bringing an end to the side booster, tail numbers B1064 and B1065, after they each flew on five previous Falcon Heavy missions.