Tesla CEO Leon Musk is a serial entrepreneur who has several companies, besides Tesla. He has taken three companies to a market value of more than $1 billion – Tesla, PayPal, and SpaceX. SpaceX makes advanced spaceships and rockets that deliver supplies to NASA space stations. Its plan to one day create a human colony on Mars is also separate from Tesla’s business. The hyper loop venture, called the Boring Company, is an underground rapid transit system that transports vehicles under and between cities to avoid traffic and reduce travel time.