Los Angeles entrepreneur Elon Musk has built a multibillion-dollar fortune running companies that make electric cars, sell solar panels and launch rockets into space. And he's built those companies with the help of billions in government subsidies. Tesla Motors Inc., SolarCity Corp. and Space Exploration Technologies Corp., known as SpaceX, together have benefited from an estimated $4.9 billion in government support, according to data compiled by The Times. The figure underscores a common theme running through his emerging empire: a public-private financing model underpinning long-shot start-ups. "He definitely goes where there is government money," said Dan Dolev, an analyst at...