seven times the speed of sound

[Phlyer]

This is cool.
http://edition.cnn.com/2004/TECH/space/ ... index.html

LOS ANGELES, California -- NASA has made aeronautics history by launching an experimental jet that reached a record velocity of just over seven times the speed of sound.

Fifty-seven years after test pilot . Yeager broke the sound barrier, NASA on Saturday launched the unpiloted research jet, in a development some observers say could change the future of space travel.

It is the first time a supersonic-combustion ramjet, or scramjet, which uses air for fuel, had traveled so fast, flight engineer Lawrence Huebner told reporters.

Scientists hope such jets will make space travel more affordable and spur commercial ventures.

Some observers compared Saturday's accomplishment to the Wright brothers' first powered flight.

The 12-foot-long (3.65-meter), X-43A experimental craft rode atop a Pegasus booster rocket that was launched from a converted B-52 bomber about 400 miles (643 kilometers) off the coast of southern California.

As planned, the X-43A plunged into the Pacific Ocean after the test and was not recovered.

Pegasus, which flew to nearly 100,000 feet, reached a speed of Mach 5, or five times the speed of sound, preliminary data on the test flight showed.

The needle-nosed scramjet then reached a maximum speed of slightly over seven times the speed of sound, or about 5,000 mph (8,000 kilometers).

"It's a great way to end, certainly all the sweeter because of all the challenges we've had to step up to and overcome through the life of this project," said Griffin Corpening, chief engineer on the project at NASA's Dryden Flight Research Center.

The first X-43A flight ended in failure June 2, 2001, after the modified Pegasus rocket used to accelerate the plane veered off course and was detonated.

An investigation board found preflight analyses failed to predict how the rocket would perform, leaving its control system unable to maintain stable flight.

NASA built the X-43A under a $250 million program to develop and test these exotic type of engines.

Saturday's flight tested aspects of a design to allow planes to overcome the pull of Earth's gravity by reaching escape velocity.

The "air-breathing" jet was not bogged down with heavy fuel tanks, Huebner said.

The space agency's dogged pursuit of extreme speed, officials hope, will ultimately make space flight easier to accomplish.

It also could drastically cut the time of commercial flights -- perhaps shortening the trip between New York and London to less than five hours.

After Pegasus released the X-43A, it flew under its own power for six minutes to do maneuvers over the ocean.

The B-52 left California at 3:40 p.m. ET, taking at least an hour to reach the launch site over the ocean. The entire test lasted only about 10 minutes.

NASA said it could test a vehicle at Mach 10 by the end of the year.

[FA28 guy]

First it was mach number then it was the flip phone now its seven times the speed of sound. why don't we just fix the trasporter and be done with it. I knew being a trecky was educational and leading eadge.

Make it so Mr. Crusher

[Maverick]

Y'a Cannot Change the Laws of Physics Capt'n....

[chewsta]

No, but we can speed up development of the Heisenburg Compensator.

[MurtsAir]

I wonder if "they" will call it Warp speed one day. just a thought

[oldtimer]

Can you imagine. Halifax to Vancouver in under an hour. That means the airline can leave 6 1/2 hours late and still be on time. In two hours your luggage could be on another continent. If, every 20 seconds, you were able to toss out an old but servicable ELT, that would keep the CF in business for a year. WOW. That progress.

[ahramin]

which uses air for fuel

And as usual they've got the facts straight. Someone should make this fool starve for a week to make sure he understands the difference between fuel and air. The X-43 is air breathing, as opposed to rocket powered, but still needs fuel to burn.

I wonder if we will ever see semi-ballistic airliners. Should have had them by now, but we seem to be regressing now instead of progressing.

[North Shore]

I think that high-speed passenger travel went the way of the dodo with the grounding of Concorde. Why? Fuel cost and burn - the faster you go, the more you burn. Slow and efficient is always the way to go... That's why you see Airbus and Boeing building bigger and more efficient airliners, and not working on SST's.

Still, an interesting technical achievement.

[N2]

Wow 7 times the speed of sound! That's faster than most flight schools can get the money out of your wallet....well pretty close!

[oldtimer]

I can see it all now. The US military are up here with their newest toys for the Abbotsford Airshow. Vancouver Terminal is working their arrival.

"SCRAMJET- Radar Identified, slow to 100 kts, if able, your #2 behind a PBY just off Naniamo. Break Break - ., your #1 keep your speed up.

"Vancouver, SCRAMJET, if we have to follow the old pig boat, we will return to Houston till he is by DAWG. Thank you."

[Cat Driver]

Just for the sake of conversation I flew for two seasons with Frances first Astronaut and we spent many thousands of miles watching the scenry go by between Toulouse and Santiago Chile.

He flew a hell of a lot faster than that, I believe he said on reentry they started into the atmosphere at 17 times the speed of sound.

The interesting part was when they had no communications with Huston due to the arurora created by the heat wave surounding the shuttle.

Anyhow I beat him in doing a short circuit with the A320 Sim at Airbus, he dragged a wing because he got to wide turning final and turned to steep to close to the runway.. So even test pilots sometimes get to agressive......

Cat

[oldtimer]

I remember watching the tube when the first shuttle was re-entering. hey had the shuttle on the ground at Edwards and the crew had not opened the door yet. So to kill time, CNN was interviewing one of the chase plane pilots who was the first to get a visual on the shuttle. He said it was a bit of a letdown for him because here he was in the hottest thing the USAF had and it was cranked up to full tilt when this glider went scooting by.

[Phlyer]

This article from the Economist explains the scramjet a bit better:

http://www.economist.com/science/displa ... id=2535926

The X-43A is powered by an engine known as a scramjet. Scramjets work on a simple principle—simpler, indeed, than the turbojets used in conventional aircraft. The engine is a tube through which air flows at supersonic speeds. While the air is in the tube, it is mixed with a fuel (in this case, hydrogen) and burned. This causes the mixture to expand. The exhaust thus goes out the back even faster than the air came in the front. Newton's third law of motion (to every action there is an equal and opposite reaction) then propels both engine and aircraft forwards.

The tricky part, according to Joel Sitz, the head of the X-43A flight-test programme at NASA's Dryden research centre, located next door to Edwards, is that the air is in the tube for mere milliseconds. Getting such details as the fuel-air mixture right is thus hard—and is made harder by the fact that what is right is different at different speeds.

At the moment, the “variable geometry” engine design needed to accommodate these differences is beyond the skill of aircraft engineers. So, to simplify the task, Saturday's flight will not require the X-43A to accelerate under its own power. Instead, it will be taken to high altitude by a B-52 bomber, dropped from the bomber, and then accelerated to Mach 7 by a booster rocket. Only then will the booster be jettisoned and the scramjet ignited.

Some readers may think that this plan sounds familiar. It is. But the last time NASA tried it, in June 2001, things went haywire a few seconds after the booster started firing. The rocket span out of control and had to be ordered to blow itself up.

An investigation concluded that data from computer simulations and wind-tunnel tests had been misinterpreted. One problem was that the rocket used as a booster (a type known as Pegasus, that is designed to be used as a satellite launcher) is usually dropped from its launch aircraft at an altitude of 12,200 metres. In 2001, the release was done at 7,000 metres. The difference in air pressure made the rocket behave abnormally, and probably contributed to the crash. Saturday's test will therefore take the sensible step of starting at 12,200 metres.

If all goes well this time, a Mach-10 flight of another X-43A will take place in July. A follow-up craft, the X-43C, is also in development. This will use a hydrocarbon fuel (think exotic petrol) rather than hydrogen. That will allow an X-43C to fly for up to five minutes, rather than a mere ten seconds. But the X-43C will still be disposable. A re-usable version, paradoxically known as the X-43B, is planned, but no money has yet been allocated to build it.

Though the X-43 project is a modest start, it could lead to bigger things. In the long term, scramjets offer the possibility of cheap access to space. That is because, unlike the rockets currently used to get into orbit, they are air-breathing. This means they do not have to carry liquid oxygen (or some other oxidant) to burn their fuel, and could thus use the weight saved to carry a bigger payload. A scramjet-powered booster could thus launch heavy loads to the edge of space. Only there would a rocket be required.