"One the main precepts of being successful in flying in space is in visualizing failure," says astronaut Chris Hadfield. And business is no different. Those who only visualize success are doomed to fail because they haven't prepared for every eventuality—"they don't recognize that something always goes wrong," says Hadfield.

One of the obvious potential failures is that anything that's single source will go away, says Hadfield. For instance, a single source of funding can vanish overnight, leaving the unprepared entrepreneur in an untenable situation. "If you're launching into orbit and you have one rocket engine on your rocket ship, if it quits, you're done," says Hadfield. "If I let myself get to this point and never considered the 100 possible failures, then all I was really doing is hoping which is no way to set up a business or launch a rocket ship," he adds.

Sometimes, aborting the mission (in other words, letting your business die) is your best option. As Hadfield says, you need to stop digging when you're already in a hole. Find out which company Hadfield thinks will fail first: Google, Facebook, Twitter or LinkedIn.