Two hour flights from Sydney to London on track for 2018 launch
Hypersonic travel that could propel people from London to Sydney in just two hours is one step closer to reality, following a successful test.
The project, which saw US and Australian military scientists combine resources, is on track to launch in 2018 after its latest engine trial hit the target speed of Mach 7.5 - more than seven times the speed of sound.
It could revolutionise global air travel and prove cost-effective access to space, Alex Zelinsky, the chief Australian scientist working on the project said.
For a jet or rocket to be classified as hypersonic, it must travel at five times the speed of sound, or Mach 5.
The latest trial at the world's largest land testing site in Australia saw a rocket hit the target speed of Mach 7.5 (5760 miles per hour), reaching an altitude of 279 kilometres.
"We want to be able to fly with a hypersonic engine at Mach 7," Michael Smart, a hypersonic expert from the University of Queensland who is working on the test, told the AFP. "You could fly long distances over the Earth very, very quickly.
"It's also very useful as an alternative to a rocket for putting satellites into space."
The team plans to run 10 trials on the rocket, which has a supersonic combustion engine that uses oxygen for fuel, making it lighter than traditional rockets.
The next test is scheduled for 2017, while the first was in 2009.
Boeing and the German space agency are also working on the project with the US and Australian militaries.
The team isn't the only group to be looking at hypersonic technology.
Earlier this year a concept design for the Antipode, which could travel from London to New York in just 11 minutes at 12,427 miles per hour, was released.
Spike Aerospace, an engineering company in Boston, also unveiled plans last year to develop a 12 to 18 seater supersonic private jet that could cross the Atlantic in under four hours.
Airbus also filed a patent for a jet called Concorde 2 that could make the journey in an hour.
What is hypersonic travel?
It is loosely defined as "Mach 5", or five times faster than the speed of sound, which would be 6,200km per hour at sea level
Why is it difficult to achieve?
In hypersonic travel, temperatures get so hot that the air molecules become unstable and start losing electrons. The air begins to change chemically and becomes an electrically-charged field
How close are we?
So far, most hypersonic test flights have been unmanned and experimental, and have lasted for no more than a couple of minutes
The X-15, operated by the United States Air Force and the National Aeronautics and Space Administration secured the official world record for the highest speed ever reached by a manned, powered aircraft in June, 2015.
Its maximum speed was 4,520 miles per hour or Mach 6.72
When was the first recorded hypersonic flight?
The V-2 rocket, first used in World War II by Nazi Germany, reached a maximum velocity of 5,150 miles per hour - more than five times the speed of sound
What's faster than hypersonic?
Hypersonic is an open-ended term. However, 'warp speed', as suggested by the Star Trek series, would be faster. Warp 9.6 is 1,909 times the speed of light