Enter Elon Musk. The man at the head of Tesla Motors is familiar with airborne vehicles thanks to his SpaceX venture and, last week, he mentioned he has an idea for an electric plane. Talking at the Charles River Ventures CEO Summit, Musk said that he's thought about a supersonic electric plane since battery technology has advanced to the point where electric aircraft are possible. Possible, but still a long way off, even for Musk. With the new Tesla Model S and other items on his to do list, Musk did admit that, "I have too much to think about."