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(CNN) -- The National Aeronautics and Space Administration conducted a third and final test flight of the unmanned X-43A aircraft, which uses an experimental scramjet engine designed to push the craft to nearly 10 times the speed of sound.

A scramjet differs from conventional jet technology by not using rotor blades to compress the air inside the engine. Instead, the scramjet, sometimes called an "air-breathing" engine, burns hydrogen fuel in a stream of fast-moving, compressed air created by the forward motion of the aircraft.

Hot exhaust shooting out of the back of the jet propels it forward at high speed.

At a post-flight news conference Tuesday, mission managers said they had only begun to look at the data, but they believed the aircraft reached a speed of about 6,600 miles (10,621 kilometers) per hour, or about Mach 10.

The flight took place over the Pacific Ocean off the coast of Southern California, in restricted U.S. Naval airspace.

The black X-43A, fastened to a larger, white booster rocket, was carried to 40,000 feet (13,157 meters) strapped to the right wing of a B-52, which took off from NASA's Dryden Flight Research Center in Edwards, California.

The B-52 released the booster rocket, which dropped for several seconds with the X-43A attached to its nose, then ignited and ascended to 110,000 feet (36,184 meters). At that point, the scramjet engine fired and the booster rocket dropped away.

As planned, the test flight lasted only a couple of minutes and ended when the aircraft ran out of fuel. It eventually crashed harmlessly into the ocean.

The test flight was originally scheduled for Monday, but technical glitches forced NASA to postpone it for 24 hours.

Tuesday's flight was the last of three test flights in NASA's eight-year, $230 million Hyper-X program, designed to help develop a new generation of spacecraft that could fly into low Earth orbit at a fraction of the current cost.

Some engineers have even speculated that scramjets could one day power a fleet of hypersonic airplanes, capable of crossing a continent in less than an hour. The technology also has military applications, with the potential for new innovations in ballistic missiles.

Scramjet technology could eliminate the need to use heavy liquid oxygen to launch spacecraft and rockets into orbit. A speed of Mach 25, or 17,000 miles (27,200 kilometers) per hour, is needed to lift a craft into orbit.

In 2001, the X-43A's maiden flight ended unsuccessfully after an onboard booster rocket misfired and flight controllers had to destroy the aircraft. But last March, its second flight was successful, reaching almost Mach 7.

However, with NASA now dedicating the bulk of its resources to returning the space shuttle fleet to flight, completing construction of the international space station and developing technology for manned missions to the Moon and Mars, no additional scramjet flights are on the drawing board.

Topher wrote:Um, no, it didn't.

Tetrad wrote:

Topher wrote:Um, no, it didn't.

I'm sure google's calculating it at sea level, which this plane definately wasn't at.

At a post-flight news conference Tuesday, mission managers said they had only begun to look at the data, but they believed the aircraft reached a speed of about 6,600 miles (10,621 kilometers) per hour, or about Mach 10.

As planned, the test flight lasted only a couple of minutes and ended when the aircraft ran out of fuel. It eventually crashed harmlessly into the ocean.

CNN wrote:Instead, the scramjet, sometimes called an "air-breathing" engine, burns hydrogen fuel...

[MS]Instig8 wrote:Sorry, son. The top speed of the SR-71 is classified. But, it's been 'know' to outrun anything you can throw at it.

roid wrote:

CNN wrote:Instead, the scramjet, sometimes called an "air-breathing" engine, burns hydrogen fuel...

it's 'CNN are dumbasses day' today

it's sometimes called an airbreathing engine? wtf. it's ALWAYS an airbreathing engine. that's like saying that a 4 stroke car engine is SOMETIMES called an internal combustion engine, or that i'm SOMETIMES called a human (hmm, bad example?).

what's with the wording CNN? give your science journos some coffee or something.

The X-43A broke its own speed record set in March of Mach 6.83.

Before this, the record for jet-powered flight was held by SR-71 "Blackbird" spy plane, flying at Mach 3.2.

Rockets and rocket-powered planes are capable of flying at greater speeds, however. The experimental X-15 rocket-engined plane flew at Mach 6.7 on October 3, 1967.

Shortly after separation, its scramjet engine operated for about ten seconds, demonstrating forward thrust in flight and obtaining unique flight data for an airframeintegrated scramjet

Ford Prefect wrote:

As planned, the test flight lasted only a couple of minutes and ended when the aircraft ran out of fuel. It eventually crashed harmlessly into the ocean.

According to the report on the radio the scram jet engine ran for 10 count'em 10 seconds.
Very interesting technology but still away to go before I can fly from LA to Sidney in 30 minutes.

[MS]Instig8 wrote:Sorry, son. The top speed of the SR-71 is classified. But, it's been 'know' to outrun anything you can throw at it.

The fastest published speed of the SR is Mach 3.5. There are several factors that limit the speed of the SR, one is the shock waves generated by various parts of the plane, at around Mach 3.6-3.8 the shock wave off the nose of the aircraft narrows enough to go into the engine, while there is the inlet spike (which slows the air to subsonic before it enters the engine), the shock wave bypasses the spike and causes the engine to unstart. Second is the heat generated by the plane moving through the atmosphere, even titanium has its limits, and the heat generated by the SR brings the fuselage to the brink. Just recently I found out that during a Lockheed Skunk Works study to see how much money and development it would take to get the SR to go faster than its designed top speed 3.2-3.5, the designers discovered (among other things) that the metal divider between the windshield was heating up so much above mach 3.5 that it was affecting the integrity of the windshield, and at that point they had stretched the glass technology to the max! So Mach 3.2 to a max of 3.5.

Now according to Richard Graham: "The design Mach number of the SR-71 is 3.2 Mach. When authorized by the Commander, speeds up to Mach 3.3 may be flown if the CIT limit of 427 degrees C. is not exceeded. I have heard of crews reaching 3.5 Mach inadvertently, but that is the absolute maximum I am aware of."

How high does the SR really fly, and do the Pilot and RSO get astronaut wings after flying the SR? The SR doesn't fly quite that high, the highest altitude I've heard attributed to the SR was 100,000 ft (18.93 miles), all the Air Force and Lockheed admit to is above 80,000 ft. To get astronaut wings you have to fly at least 264,000 ft (50 miles). Which the SR (even though it's a fantastic aircraft) doesn't get close to that altitude!

Richard Graham contributes: "The SR-71s engines require a sufficient quantity of air in order to operate. The maximum altitude limit is 85,000 feet unless a higher altitude is specifically authorized. Again, I have heard of crews inadvertently reaching 87,000 feet, but no higher."

Ford Prefect wrote:Surely this thing is not a defence secret of some kind.