The space race between the capitalist US and communist USSR saw decades of competition to push the boundaries of what mankind could achieve in space, all in the name of ideological superiority.

Now, a new contest is under way, but instead of a clash of cultures, this is a clash of egos - between two billionaires who made their fortune on the internet.

But Amazon's Jeff Bezos and Tesla's Elon Musk don't simply want to get us back to space - they want us to stay there.

Produced by James Wignall