Air Force set to fly Mach-6 scramjet

[GAP]

Air Force set to fly Mach-6 scramjet
Air Force set date for first flight test of hypersonic jet
By Layer 8 on Fri, 05/21/10
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The US Air Force said it was looking to launch its  14-foot long X-51A Waverider on its first hypersonic flight test attempt May 25.

The unmanned X-51A is expected to fly autonomously for five minutes,  after being released from a B-52 Stratofortress off the southern coast of California.  The Waverider is  powered by a supersonic combustion scramjet engine, and will accelerate  to about Mach 6 as it climbs to nearly 70,000 feet.  Once flying the X-51 will transmit vast amounts of data to ground stations about the flight, then splash down into the Pacific.  There are no plans to recover the flight test vehicle, one of four built, the Air Force stated.

Hot space projects produce cool cosmic discoveries

"In those 300 seconds, we hope to learn more about hypersonic flight with a practical scramjet engine than all previous flight tests combined," said Charlie Brink, X-51A program manager with the Air Force Research Laboratory's Propulsion Directorate. Since scramjets are able to burn atmospheric oxygen, they don't need to carry large fuel tanks containing oxidizer like conventional rockets, and are being explored as a way to more efficiently launch payloads into orbit.

The longest previous hypersonic scramjet flight test performed by a NASA X-43 in 2004 was faster, but lasted only about 10 seconds and used less logistically supportable hydrogen fuel, the Air Force stated.

Hypersonic combustion generates intense heat and routing of the engine's own JP-7 fuel will help keep the engine operating properly, the Air Force stated. As the scramjet engine ignites it will initially burn a mix of ethylene and JP-7 jet fuel before switching exclusively to JP-7.

The Air Force describes the X-51 as virtually wingless, designed to ride its own shockwave. The heart of the system is its Pratt & Whitney Rocketdyne SJY61 scramjet engine, but other key technologies will be demonstrated including thermal protection systems materials, airframe and engine integration, and high-speed stability and control.

The Air Force said this will be the only hypersonic flight attempt this fiscal year, a change from the original test plan which was to fly in December 2009 then three more times in 2010.
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[DexOlesa]

Should be interesting. Here's hoping for a smooth flight, and lots of useful data.

 

[aesop081]

It is worth noting that flight at those speeds is not new. The X-15 flew at Mach 6.04 on November 9, 1961; and Mach 6.7 on October 3, 1967. What is significant here is the method of propulsion.

 

[Fishbone Jones]

It is worth noting that flight at those speeds is not new. The X-15 flew at Mach 6.04 on November 9, 1961; and Mach 6.7 on October 3, 1967. What is significant here is the method of propulsion.

........and, I dare say, the type of fuel. Being able to use an existing and common fuel, vice some possible highly volitile exotic fuel, has to be a big plus.

 

[a_majoor]

USAF concludes the X-51 program with a sucessful test flight:

http://www.wpafb.af.mil/news/story.asp?id=123346970#.UYP7MAFwlrU.facebook

X-51A Waverider achieves history in final flight

Posted 5/3/2013  Updated 5/3/2013 

by Daryl Mayer
88th Air Base Wing Public Affairs

5/3/2013 - WRIGHT-PATTERSON AIR FORCE BASE, Ohio -- The final flight of the X-51A Waverider test program has accomplished a breakthrough in the development of flight reaching Mach 5.1 over the Pacific Ocean on May 1 a little after 10 a.m. Pacific Time.

"It was a full mission success," said Charlie Brink, X-51A program manager for the Air Force Research Laboratory Aerospace Systems Directorate.

The cruiser traveled over 230 nautical miles in just over six minutes over the Point Mugu Naval Air Warfare Center Sea Range. It was the longest of the four X-51A test flights and the longest air-breathing hypersonic flight ever.

"I believe all we have learned from the X-51A Waverider will serve as the bedrock for future hypersonics research and ultimately the practical application of hypersonic flight," Mr. Brink said.

The X-51A took off from the Air Force Test Center at Edwards AFB, Calif., under the wing of a B-52H Stratofortress. It was released at approximately 50,000 feet and accelerated to Mach 4.8 in about 26 seconds powered by a solid rocket booster. After separating from the booster, the cruiser's scramjet engine then lit and accelerated to Mach 5.1 at 60,000 feet.

After exhausting its 240-second fuel supply, the vehicle continued to send back telemetry data until it splashed down into the ocean and was destroyed as designed. All told, 370 seconds of data was collected from the experiment.

"This success is the result of a lot of hard work by an incredible team. The contributions of Boeing, Pratt and Whitney Rocketdyne, the 412th Test Wing at Edwards AFB, NASA Dryden and DARPA were all vital," said Mr. Brink.

This was the last of four test vehicles originally conceived when the $300 million technology demonstration program began in 2004. The program objective was to prove the viability of air-breathing, high-speed scramjet propulsion.

The X-51A is unique primarily due to its use of a hydrocarbon fuel in its supersonic combustion ramjet, or Scramjet, engine. Other vehicles have achieved hypersonic - generally defined as speeds above Mach 5 - flight with the use of hydrogen fuel. Without any moving parts, hydrocarbon fuel is injected into the scramjet's combustion chamber where it mixes with the air rushing through the chamber and is ignited in a process likened to lighting a match in a hurricane.

The use of logistically supportable hydrocarbon fuel is widely considered vital for the practical application of hypersonic flight.

As a technology demonstration program, there is no immediate successor to the X-51A program. However, the Air Force will continue hypersonic research and the successes of the X-51A will pay dividends to the High Speed Strike Weapon program currently in its early formation phase with AFRL.

 

[jollyjacktar]

Impressive, but you gotta admit they're really expensive remote controlled airplanes for such a short journey.  It will be interesting to see what they do and how far/fast they run with this new knowledge gleaned from the tests.

 

[Kat Stevens]

We'll develop the most advanced multi role fighter/bomber/spy plane, then promptly destroy the prototypes and destroy the schematics in order to get a real nifty missile system, or something like that.

 

[PAdm]

Ladies and gentlemen, welcome to the USAF.  Please keep your hands inside the ride....