July 16, 2013 9:30am EDT | Updated prev Elon Musk, Chief Executive of Tesla Motors and SpaceX, smiles during the Reuters Global Technology Summit in San Francisco June 18, 2013. (Reuters) Billionaire entrepreneur Elon Musk has revealed more information on his top-secret Hyperloop -- a vehicle he says will take passengers from Los Angeles to San Francisco in a mere half hour. The Tesla Motors co-founder called the fast train "a cross between a Concorde and a railgun and an air hockey table" at the D11 Conference earlier this year. The pneumatic tube train system will be "twice as fast as what an average aircraft can do." And in a tweet yesterday, he promised to publish the alpha design by August 12 and asked for feedback from his followers. Once constructed, the Hyperloop will leave as soon as passengers board as opposed to running on a strict schedule. The train will also be weather immune which might put a damper on some people who still enjoy the occasional snow day. More On This...