Half a century after astronaut Neil Armstrong became the first man on the moon, a new space race is underway to exploit the skies for commercial profit.
Tech giants and startups pursuing bold plans such as selling space tourism, mining asteroids and beaming giant adverts into the skies are winning millions in investment with pledges to bring the stars into reach.
Annual revenues from space-related business - currently worth $350 billion - could nearly triple in size by 2040, estimates US investment bank Morgan Stanley.
But the rapid growth of a market with seemingly boundless potential has sparked concerns about a lack of laws and potential conflicts over resources, prompting calls for more rules to govern humanity’s use of the cosmos.
“By 2040 (we believe) there will be 1,000 people living and working on the moon and 10,000 annual visitors,” said Aaron Sorenson, a spokesman from the Japanese lunar exploration startup ispace, inc.
“Our company vision is to extend human presence into outer space. We believe that begins with the expansion of the earth’s economy to the moon,” he said.
Drops in launch costs brought about by technological advances such as the development of commercial reusable rockets have caught the interest of startups and investors.
Super-rich businesspeople including Tesla Inc chief executive Elon Musk and Amazon.com Inc founder Jeff Bezos who want to colonise space to support human life are pouring cash into cutting-edge private spacecraft.
In addition, a resurgence in national space programmes of countries such as India - which this week launched a rocket aiming to get a rover on the moon - as well as the United States and China could provide a source of funding for businesses.
Space hotels, cosmic business insurance, celestial advertising billboards, and in-space manufacturing are among the businesses being explored by firms hoping that technology will open up new horizons amid a boom of commercial space activity.
“I think very soon you are going to see major, traditional non-space businesses taking notice,” said Sorenson, whose company is working to develop a high-frequency shuttle between earth and the moon.
Aerospace companies such as Musk’s SpaceX and Bezos’ Blue Origin are aiming to become the first private firm to launch a human into space.
A handful of firms have also been exploring the potential of mining asteroids for minerals and resources, a business that for now remains in the realm of science fiction but which space companies think could be possible in a decade or two.
Governments are positioning to take advantage of these new markets even before they become a reality.
The United States and Luxembourg have both passed legislation aiming to allow property rights on planets and create regulations to permit space mining, with Russia indicating earlier this year that it may follow suit.
But it is doubtful whether some of the more futuristic firms have yet established a clear business model, said Ian Christensen from the Secure World Foundation, a space advocacy group.
The rush of speculation in space has also revealed gaps in the international laws and treaties governing its use and sparked calls for greater oversight.
The 1967 Outer Space Treaty - with more than 100 nations party to the agreement - provides the main framework for space law, and says no nation can claim ownership of outer space and it must be free for use by all countries.
“In those days everybody thought that space was basically for a few states, for military purposes,” said Frans von der Dunk, a professor of space law at the University of Nebraska-Lincoln.
“Nobody really foresaw the commercial development which we have seen since. So in that sense a lot needs to be clarified.”
Key questions include whether companies can claim ownership over space minerals, according to von der Dunk. If so, how should countries divide up access rights to ensure the spoils are shared fairly?
There is also debate about how to deal with the growing amount of “space junk” hurtling around the earth, such as broken satellites and spent rocket parts, which can cause serious damage to spacecraft.
“If it goes on like this then maybe 10 or 20 years from now it will be nearly impossible to conduct safe space operations because there’s so much junk floating around,” said von der Dunk.
Another worry is that plans by companies like Amazon and SpaceX to launch thousands of satellites will jam space with yet more clutter and increase the risk of collisions, said Christopher Newman, a space law and policy expert from Britain’s Northumbria University.
Clarifying the rules of doing business in space could benefit commercial operators by offering them stability and clearer costs and risks, say legal experts.
But the likelihood of world powers agreeing to any major new international space treaties or a body to referee disputes between nations are slim, said Newman.
He added that treaties which give away sovereignty are “out of fashion”.
Until a clearer picture emerges of the future of space infrastructure, he said, space players will continue to enjoy a degree of “anarchy”.
“Space is congested, competitive and contested ... and it’s only going to get worse as the technology, orbital population and access to space all increase,” he said.