JEFF Bezos may be the richest man who ever lived but he is not one to squander his wealth on meaningless luxuries. Bezos, the founder and CEO of Amazon, is liquidating some $1 billion a year of Amazon stock to finance his remarkable ambitions for space through his main passion: the space company, Blue Origin. It develops technologies aimed at enabling human access to space "at dramatically lower cost and increased reliability.”

Bezos, whose net worth is reckoned to be $112 billion, has been fascinated with space since he was very young. He is also one of a handful of billionaire innovators who are intent on exploring the final frontier.

The example of Bezos, Elon Musk and others is a reminder that, in the States, space exploration, once pioneered by Nasa, is now in the hands of private individuals with the means to launch, in Bezos’s words, a “dynamic entrepreneurial explosion in space”.

Blue Origin is developing a vertical rocket equipped with a capsule capable of carrying passengers, and Bezos, 54, believes that there will, eventually, be human settlements beyond Earth as we become a space-faring civilisation.

“We have sent robotic probes now to every planet in the solar system,” he told Prof Brian Cox in the BBC documentary, The 21st Century Race for Space, “and we know, without any shadow of a doubt, that Earth is the best one. We need to protect it, and the only way to really protect it is to eventually move heavy industry off Earth, and Earth can be effectively zoned, residential and light industry.”

Space is a “much better place to do heavy manufacturing … you have 24/7 solar power, resources in space are much vaster in terms of mineral resources and so on …. And so, over the next couple of hundred of years, that will allow us to both continue to have a dynamic, expanding, growing, thriving, interesting civilisation, whilst still protecting this planet that we evolved on.”

Both Blue Origin and Sir Richard Branson’s Virgin Galactic passed key space-faring milestones last month. The latter’s SpaceShipTwo VSS Unity successfully completed her first supersonic, rocket-powered flight. On April 29 Blue Origin successfully launched a recycled rocket, the RSS H.G. Wells, carrying a crew capsule to an altitude of 351,000 feet. Together, the milestones bring the tantalising prospect of space tourism that much closer.

Both Bezos and Branson reportedly hope to take paying customers into space by year’s end. “This is really happening,” Christian Davenport, author of a new book, The Space Barons, said last week. “What Branson and Bezos want to do is make it easier for more people to see the curvature of the earth, see the blackness of space, and see the thin blue-greenish hue of the atmosphere and the land below without any boundary lines.”

Virgin Galactic has experienced delays and other setbacks. In October 2014 its SpaceShipTwo disintegrated during a test flight in the Mojave desert. Co-pilot Michael Alsbury was killed.

“Richard Branson has been promising and promising that space tourism flights were right around the corner,” Davenport said. “But now it does seem like he’s finally very close.” Branson himself tweeted on April 6: “Thrilling seeing our manned spaceship go supersonic for the first time. Lots of hard work to come and exciting days ahead as we get closer & closer to space.”

Cox was filmed last year at the controls of SpaceShipTwo in the company of Scots-born Dave Mackay, Chief Pilot at Virgin Galactic. He took a degree in Aeronautical Engineering at Glasgow University, joined the RAF and then, in 1995, joined Virgin Atlantic.

The current price for a flight is around $250,000 but Branson told Cox: “The cost of our programme has been a lot more than we thought. Once we’ve got our investment back and once we’ve got a number of spaceships, I think we can start seeing the price coming down. One day, we could have 20 spaceships operating and then the price could come down to a level where, I think, there would be much, much, much more demand than we can ever supply. So I think an enormous number of people will be able to go into space.”

Virgin Galactic’s sister operation, Virgin Orbit, is a rocket company that aims to take small satellites into space.

A third billionaire now laser-focused on space is PayPal founder Elon Musk, 46. His company, SpaceX, was formed 16 years ago with the ultimate goal of enabling people to live on other planets.

SpaceX recently launched and landed the Falcon 9 Block 5, the latest version of its reusable rocket. Musk himself tweeted recently that the goal of the next generation of SpaceX rocket, the ‘BFR’, will be “to enable anyone to move to [the] moon, Mars & eventually outer planets.”

In a speech last September Musk said it was his ambition to take people to Mars by 2024 to begin preparing for human expansion. He wants to have cargo ships land on the Red Planet by 2022. “I feel fairly confident we can build the ship and be ready for the launch in five years,” he said. “Five years feels like a long time for me.”

There is no doubt that the colossal potential of space is close to many people's hearts.

This week will see the annual Space Tech Expo, in Pasadena, Los Angeles. Scientists, engineers, executives, government representatives, policy makers, space agencies, military and entrepreneurs will discuss the key challenges and opportunities in civil and commercial space.

Many companies have poured huge sums into space-related research, with an eye on the future. One, Deep Space Industries hopes to enable the human expansion into space “by harvesting space resources such as rocket fuel, water, construction materials, and precious metals. These are the building blocks that will eventually allow large numbers of people to live and work in space, and they are all available in effectively limitless quantities from Near-Earth Asteroids.”

In space, it seems, the only limit is your imagination.