For a man who has just made a cool $1.5bn from the sale of his PayPal Internet business to eBay, Elon Musk seems quite relaxed about it all. The youthful Mr Musk has had some practice in these matters. A previous venture (Zip2 — maker of software for the media industry) was sold to Compaq for $300m in 1999. Now flush with eBay’s cash, Musk has set up his third company, SpaceX, an organisation with the not unambitious goal of creating a permanent manned settlement on Mars — though all he offered about this on Monday was that “we’re building a rocket in LA.”