This is SpaceX's tenth supply mission for the International Space Station, but the Dragon capsule on the rocket is carrying a special payload. It's hauling an experimental module, Raven that will test autonomous space rendezvous technology: its three-sensor array will track spacecraft visiting the station and help guide them safely to their intended destination.

Expect launches from 39A and elsewhere to be relatively commonplace. SpaceX vowed that it would launch rockets every 2 to 3 weeks, and it's clearly making good on that promise so far. The company is clearing its backlog of launches following the September explosion and wants to satisfy customers (including NASA) who've been waiting months to get cargo into orbit.