The Boeing Phantom Ray unmanned airborne system sits atop a NASA Shuttle Carrier Aircraft (SCA), a modified Boeing 747. The two aircraft made aviation history on the same flight, thanks to some way-out-of-the-box thinking and a special adapter, both courtesy of Boeing engineers. The Phantom Ray and the adapter weigh approximately 30,000 pounds together, but weight was not an issue, since the shuttle orbiter weighs 220,000 pounds while being ferried on an SCA.