A group of US billionaires is planning a daring space mission to extract fuel and precious metals from asteroids as they whiz past Earth at millions of kilometres per hour.

The entrepreneurs include film director James Cameron, Google bosses Larry Page and Eric Schmidt and the space tourism pioneer Eric Anderson.

They're not the first to announce plans to mine asteroids in space, but they are the best funded.

A group of US billionaires is planning a daring space mission to extract fuel and precious metals from asteroids as they whiz past Earth at millions of kilometres per hour.

The entrepreneurs include film director James Cameron, Google bosses Larry Page and Eric Schmidt and the space tourism pioneer Eric Anderson.

They're not the first to announce plans to mine asteroids in space, but they are the best funded.

Their firm will be called Planetary Resources.

Thomas David Jones of Planetary Resources explained: "I've been to a lot of launches, some pretty exciting ones. I don't think I've been to one that's as significant though for the future of our society and for our future exploration and residence permanently in space ... by harnessing these resources that await us in space on the nearby asteroids."

The idea is to launch a telescope capable of tracking asteroids, lumps of rock left over from the Big Bang that are still hurtling through space, as they pass-by the Earth.

A whole fleet of telescopes will follow. Eventually, a space depot will come into operation with the ability to mine an asteroid for resources like ice, fuel, and precious minerals such as gold and platinum.

There's a lot of excitement within the scientific community about the prospect of mining asteroids cost effectively.

Roger Launius, who was NASA's historian, is now chief space curator at the Smithsonian National Air and Space Museum in Washington DC.

Lanius told me: "It's another example of one of the great possibilities that we have before us. This is one of the reasons why the second 50 years in space, I believe, are going to be more exciting than the first 50 years. But we still have to be aware that we're not there yet. If we can actually realise that promise and achieve that end it's going to go a long way toward making us a true space-faring people and that's our objective, ultimately."

Space experts say the key to asteroid success will be getting the first telescope launched and into orbit. After that, they say, things should begin falling into place.

Meanwhile, the billionaires say they are prepared for a little ribbing over their idea. Still, given time and money - especially money - they reckon they can transform what, until now has been a storybook idea, into reality.