NASA wants to bring robot planes to US skies

The biggest obstacle to having commercial airliners flown entirely by computers isn't technical. Sure, there's lots more that needs to be done, which is why NASA is launching a pilot program to test out pilotless aircraft (pun intended), but no matter how safe (or even safer) a robot plane might be, there is something oddly disconcerting about the thought that there might not be anybody at all sitting up in the cockpit. NASA says they hope that unmanned planes could be sharing airspace with regular aircraft within four years.