The US space agency is already working with Elon Musk's SpaceX firm, and it's now joined forces with Bezos' Blue Origin company, which will build a landing craft to take a crew down to the lunar surface.

Agency Administrator Bill Nelson said in a statement: "We go to the Moon, to learn, to live, to invent, to create all these things to be successful at the Moon, to go to Mars. The great adventure of humankind pressing out into the cosmos is here. And this is a part of it."

Blue Origin - which was founded by Bezos, the owner of Amazon, in 2000 - will receive $3.4 billion from Nasa under the terms of their agreement.

John Couluris, who is Blue Origin's vice president for lunar transportation, has been discussing the company's part in the ambitious project.

He explained: "Before the first crew landing occurs, we will be landing an exact copy of that lander prior to that - one year prior. So, we will be testing out full lander systems and the full architecture prior to any astronauts entering the vehicle."