Earlier this week, the badass X-47B drone became the first ever unmanned aircraft to refuel while in the air. Think about how cool this is, the drone has to meet the KC-707 tanker plane in the air, position itself perfectly to snatch onto the fuel line and then gas itself up with no one on board. So freaking cool.
Here's a closer shot below. You can find out more about the X-47B refuelling here.