The Bush administration has staked an aggressive new claim to dominate space - rejecting any new treaties that seek to limit the United States' extraterrestrial activities and warning that it will oppose any nations that try to get in its way.
A new policy recently signed by President George Bush, asserts that his country has the right to conduct whatever research, development and "other activities" in space that it deems necessary for its own national interests.
The new policy further warns that the US will take those actions necessary to protect its space capabilities "and deny, if necessary, adversaries the use of space capabilities hostile" to those interests. The document adds: "Space activities have improved life in the United States and around the world, enhancing security, protecting lives and the environment, speeding information flow serving as an engine for economic growth and revolutionising the way people view their world and the cosmos."
"Freedom of action in space is as important to the United States as air power and sea power."
In some respects the policy represents the space equivalent of the "Bush Doctrine" national security policy initially outlined by Mr Bush in a speech at West Point military academy in June 2002. At that event - and later more formally codified - Mr Bush said the new US policy would place more emphasis on military pre-emption and unilateral actions.
Some experts believe the space directive, discreetly published more than a week ago and barely noticed outside specialist circles, puts the US on a new and dangerous course given that it transports "Bush Doctrine" policy to a new arena and rejects any efforts to limit US behaviour.
"I think that saying we will not have any limits on our actions is quite dangerous," said Theresa Hitchens, director of the Washington-based Centre for Defence Information.
"It claims no one can prohibit our rights but it also denies rights to [others].
"You would think that we would have learnt our lessons about the danger of military pre-emptive action and unilateralism in Iraq yet we are repeating the same policy towards space."
In part the new directive builds on the space policy of the Clinton administration. But some believe its new, hardline rhetoric will increase international suspicions that the US is seeking to develop and deploy weapons in space.
"The Clinton administration opened the door to developing space weapons but that administration never did anything about it. The Bush policy now goes further," Michael Krepon, of the Stimson Centre, told The Washington Post.
Mr Bush's attitude to space has always been more ambitious than that of his predecessor. In 2004 he outlined a vision to restart sending astronauts to the Moon, and even to Mars. In the same year the US Air Force published a highly controversial plan for establishing weapons in space, amid speculation that advanced lasers, spacecraft and space-based weapons firing 100kg tungsten bolts were being developed. And earlier this year it was revealed that the Pentagon was seeking hundreds of millions of dollars from Congress to test and develop space weapons.
In those portions of the new policy document that have been made public, there is no specific mention of the weaponisation of space. It says the US's priorities are to "strengthen the nation's space leadership" and to enable "unhindered US operations in and through space to defend our interests there". But the policy also claims that national security is "critically" dependent upon space capabilities. As a result it calls on the Defence Secretary, Donald Rumsfeld, and the Director of National Intelligence, John Negroponte, to "develop and deploy space capabilities that sustain US advantage and support defence and intelligence transformations".
In recent years some nations have called for talks to ban the deployment of weapons in space. Currently the deployment of nuclear weapons or other weapons of mass destruction are prohibited by the 1967 United Nations Outer Space Treaty.
When proposals to ban the weaponisation of space have been put forward at the UN, the United States has routinely abstained. But last October the US voted against a UN resolution calling for the banning of weapons in space.
Likewise, the US has repeatedly resisted efforts to hold negotiations on the issue of banning the placement in weapons by the Geneva-based Conference on Disarmament.
Wade Boese of the Arms Control Association said the language in the new policy was "much more hard line" than any that previously existed.
He added: "We believe that this allergy to treaties is counter-productive. The US has the most to lose if there is an arms race in outer space in the long run. If the US [puts weapons in space], other countries will respond in some way."
A spokesman for the White House's National Security Council said in a statement that the policy was needed to "reflect the fact that space has become an even more important component of US economic, national and homeland security".
The final frontier
President Bush announced his Vision for Space Exploration in January 2004, calling for humans to return to the Moon by the end of the next decade. The first wave of robotic probes is the Lunar Reconnaissance Orbiter, due to launch in 2008. As well as seeking landing sites, it will search for water ice and other resources. The initiative is supported by 68 per cent of Americans, according to opinion polls.
Under President Bush's 2004 vision, Moon exploration would pave the way for human space travel to Mars and beyond. The Mars reconnaissance Rover arrived on the Red Planet on 10 March 2006, equipped with the most powerful telescope ever taken to another planet.
The Clinton administration in 1999 revived Ronald Reagan's "star wars" space-based anti-missile shield as the Pentagon pushed for a more aggressive military posture in space amid warnings that North Korea, Iran and Iraq could obtain nuclear weapons. The programme became known as "son of star wars". Space weapons could include lasers that can shut down rival satellites and "killer" satellites that could ram others.
The new Bush policy calls for space-based capabilities to support missile-warning systems, and "multi-layered and integrated missile defences" that could lay the groundwork for the militarisation of space.Reuse content