Feeds

X-51 ordinary-fuel scramjet to fly in December

Could offer scope for combo turbo/scram runway jets

High performance access to file storage

Flight tests of a powerful US military scramjet prototype able to exceed Mach 4 while burning ordinary jet fuel have been scheduled for December, according to reports.

Aviation Week reports today that the X-51 "WaveRider" scramjet will now fly in December. The X-51 will be released from a B-52 bomber mothership operated by NASA above southern California. A modified missile booster rocket will accelerate the test stack past Mach 4, after which the 25-foot-long X-51 will ignite using ethylene lighter fluid, easier to get burning in a very fast airstream.

The purpose of scramjets is to beat the speed limitations of ordinary ramjets, which slow their internal air intake stream down to subsonic speeds. Unfortunately this produces unacceptable levels of drag and fuel consumption above Mach 3 to 4, hence the desire for a supersonic-combustion ramjet - a scramjet.

To date, most successful scramjet tests have been carried out using hydrogen fuel, which is relatively easy to keep burning in a supersonic airflow. But hydrogen is expensive and dangerous to handle in large quantities, besides taking up enormous storage volumes - any hydrogen fuelled aircraft or missile would be mainly fuel tank.

In the X-51, regular JP-7 jet fuel will swiftly replace the initial ignition stream of burning ethylene. This will permit WaveRider type engines to propel much more practical aerospace craft or missiles, if it works. After flying for several minutes at a speed of almost 5000 mph (in excess of Mach 6), the X-51 test vehicles will splash down into the Pacific.

According to Charlie Brink of the US Air Force Research Laboratory, quoted by Av Week, the planned four X-51 test shots could allow scope for trying to ignite the scramjet at lower speeds and temperatures.

“The lower it can go, the lower the stress on a turbine,” said Brink.

A major aspiration of scramjet designers is to achieve a design which could be brought up to ignition speed by an ordinary jet engine rather than a booster rocket. This would potentially allow the construction of reusable aircraft able to take off and land from runways in normal turbojet mode, then accelerate to hypersonic speed once airborne. Quite apart from military uses - perhaps a successor to the legendary Mach-3.5 Cold War turbo/ramjet "Blackbird" spyplane - such craft might develop into much cheaper access to space.

The Pentagon formerly had an ambitious plan for a "Blackswift" runway plane able to do a barrel roll at Mach 6, but it was cancelled last year. Now the hopes of hypersonics fanciers are riding mainly on the X-51 and - perhaps in future - the "Project Vulcan" bomb/jet scheme. ®

High performance access to file storage

More from The Register

next story
Elon Musk's LEAKY THRUSTER gas stalls Space Station supply run
Helium seeps from Falcon 9 first stage, delays new legs for NASA robonaut
Solar-powered aircraft unveiled for round-the-world flight
It's going to be a slow and sleepy flight for the pilots
Russian deputy PM: 'We are coming to the Moon FOREVER'
Plans to annex Earth's satellite with permanent base by 2030
LOHAN's Punch and Judy show relaunches Thursday
Weather looking good for second pop at test flights
Saturn spotted spawning new FEMTO-MOON
Icy 'Peggy' looks to be leaving the outer rings
Discovery time for 200m WONDER MATERIALS shaved from 4 MILLENNIA... to 4 years
Alloy, Alloy: Boffins in speed-classification breakthrough
India's GPS alternative launches second satellite
Closed satnav system due to have all seven birds aloft by 2016
Curiosity finds not-very-Australian-shaped rock on Mars
File under 'messianic pastries' and move on, people
Top Secret US payload launched into space successfully
Clandestine NRO spacecraft sets off on its unknown mission
prev story

Whitepapers

Securing web applications made simple and scalable
In this whitepaper learn how automated security testing can provide a simple and scalable way to protect your web applications.
Five 3D headsets to be won!
We were so impressed by the Durovis Dive headset we’ve asked the company to give some away to Reg readers.
HP ArcSight ESM solution helps Finansbank
Based on their experience using HP ArcSight Enterprise Security Manager for IT security operations, Finansbank moved to HP ArcSight ESM for fraud management.
The benefits of software based PBX
Why you should break free from your proprietary PBX and how to leverage your existing server hardware.
Mobile application security study
Download this report to see the alarming realities regarding the sheer number of applications vulnerable to attack, as well as the most common and easily addressable vulnerability errors.