Image copyright Getty Images Image caption The US military is interested in using hypersonic technology to counter China’s massive military buildup
The US military has launched three hypersonic rockets from the Nevada desert in a “demonstration” of anti-missile and hypersonic technologies.
It is the latest phase of an experiment aimed at testing techniques that could be used to counter China’s military ambitions.
The rockets, developed by Boeing, were successfully sent into space by a modified Boeing Delta IV booster on Friday.
The vehicles “visited” and returned to Earth on solid-propellant boosters at an altitude of about 18 miles (29km).
Hypersonic flights – which can travel at twice the speed of sound – are a new weapons frontier in the global arms race.
China has invested heavily in development of hypersonic weapons, and is developing a range of systems for intercepting and attacking its enemies at speed.
China’s hypersonic aircraft are no longer specialised weapons, but they are still some of the fastest machines in the world.
The nation says it possesses the missiles that can strike anywhere in the world with intercontinental ballistic missiles in under 10 minutes, so no-one can doubt its capability to strike other nations.
Missile defence and hypersonic aerospace developments are both being closely watched for signs of warfare.
President Donald Trump’s administration has put budget pressures on the Pentagon to make use of programmes like the hypersonic aerospace technology.
Image copyright Getty Images Image caption A previous hypersonic rocket launched in 2015
Lieutenant General Robert Ashley, Air Force deputy chief of staff for strategic plans and requirements, said earlier this year that hypersonic air-breathing weapons could be employed in time for “the collapse of the communist empire”.
Some believe that hypersonic technologies, if developed, could enable military forces to travel hundreds of miles at high speed without being detected.
Early hypersonic technologies such as supersonic aircraft, hypersonic missiles and cruise missiles have been tested, but they have not lived up to their extreme claims.
But aerospace experts point out that more traditional hypersonic launch vehicles have also failed.
A hypersonic military technology used by Germany was destroyed by the Soviet Union in a secret event in 1960.
Image copyright Getty Images Image caption A hypersonic rocket launched in 2015 was destroyed by the Soviet Union in 1960
Moscow claimed that the Deutsches Elektronen Mehrcameorolgies AG weighed 800kg (1,572lbs) when it disappeared, but it turned out to be much lighter.
The USSR could not put it on a target, even with precision-guided munitions, and so struck the rocket from a height of 18 miles (30km).