X-43

The X-43 is an experimental aircraft built for NASA, who also refers to it as the Hyper-X. It is designed solely to test the feasibility and operating characteristics of a hypersonic SCRAMjet propulsion system and the airframe required to fly it.

There will be at least three X-43 tests (X-43A, B and C). In the first test, a B-52 test plane will drop the X-43A over the Pacific ocean. A booster rocket will fire to both lift the aircraft to its test altitude of 100,000 feet as well as to a speed high enough to ignite its SCRAMjet. If all goes well, it will accelerate under its own power to approximately 7,500 MPH (Mach 10) and maintain flight for perhaps fifteen seconds before exhausting its fuel and plunging into the Pacific. NASA does not plan on recovering it, and will be retrieving all results by telemetry. The first flight is currently (April 2001) scheduled for mid-May 2001.

A working scramjet aircraft would be extremely useful not only for high-speed transport around the globe, but also for access to space. Since a scramjet is air-breathing, the weight of consumables it is required to carry during flight in the atmosphere is dramatically cut through the elimination of liquid oxygen (LOX) supplies on board.

The current speed record for a fixed-wing aircraft is approximately Mach 6.7, set by the American X-15 test aircraft in the 1960s and 1970s. The X-15 was rocket-propelled, however, requiring both propellant and oxidizer stores to be carried onboard.

I hate it when my scramjet test platform departs from controlled flight. Better luck next time.

Oh. The X-43 is unmanned, and fairly small as self-propelled supersonic machines go -- about 12 feet long. It looks exceedingly cool though -- a sleek black wedge that Darth Vader would probably covet.

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CNN.com simply said it "fell into the ocean". Someday I'm going to write up a node about the observed accuracy of major news media -- every time I know anything about the subject, I find factual errors in newspaper articles, for example. I try to remember this when reading the other articles on subjects I know little about.

It is important to note that the X-43 didn't fail, the scramjet principle didn't fail. It never got that far. The B-52 released the Pegasus rocket, which was intended to carry the X-43 up to a burst speed at which the X-43 would be launched and its scramjet engines could cut in and take it to Mach 10.

What happened yesterday (2 June 2001) is that the Pegasus booster rocket went wrong. At time of writing it's not known how, but F-18 jets tracking it reported that it veered off course within seconds. Parts were breaking off it. NASA detonated on-board explosives to destroy it at about 7 km above the Pacific, seconds after it left the B-52.

The X-43 itself was never released. This is in no way a setback for the intrinsic technology, only for the support methods. NASA are disappointed, but the recording equipment on board the Pegasus should allow them to track why it underwent catastrophic failure.

On 27 March 2004 the X-43A was successfully launched from a height of 12 000 m, detached from its rocket at 30 000 m, and attained a self-propelled speed of Mach 7 in a flight lasting ten seconds. It then glided and manoeuvred over the Pacific Ocean before splashing down. This speed attained is twice that of the previous fastest (except rockets), the SR-71 Blackbird.

On June 2, 2001, NASA's first scramjet test was aborted after a serious failure of the rocket booster intended to bring the craft up to speed. According to NASA, the Pegasus booster went wildly off-course, forcing them to detonate on-board explosives to stop it.

The X-43A test craft was attached to the booster and lifted to a safe distance by a B-52 bomber. The booster and jet were then detached, at which time the rocket was ignited to lift the X-43A to 100,000 feet before turning the scramjet on. Had the booster not failed, the X-43A would have been active for 10 seconds, covering 17 miles at a burst of over Mach 7, or 5,000 miles per hour before being coasted to a stop on the water below.

After the X-43A is re-tested, another two tests are planned for the X-43B and C, to further test scramjet technology.

March 27, 2004
The X-43A was successfully flown today. The hypersonic scramjet was launched from a B52, then elevated to 95,000 feet by a rocket booster. At this point, it flew under its own power for 10 seconds, reaching the predicted top speed of Mach 7. It glided for several minutes for gather aerodynamic data.

The X-34A is a NASA sponsored, unmanned disposable jet. Developed under the Hyper-X program, the craft cost $230,000,000. Its goal is to act as a prototype for the scramjet engine.

Dimensionally, the jet is quite small, only 12 feet in length. It is a black jet that looks more like a paper airplane than a real jet. While it does appear to have wings, the tail is more prominent. The top of the jet is quite flat which probably helps to generate lift.

The process is similar to how a missile works. The X-34A is dropped from a B-52B at about 40,000 feet. A Pegasus rocket booster carries it up to about 100,000 feet. Once the rocket booster's fuel has been fully expensed, it drops off, letting the actual jet fly by itself on its own power. The most interesting part of the jet is that the fuel it burns will only work at speeds over mach 5 and that during the entire self-sustained burn, it consumed only 2 pounds of fuel. It is right after the rocket falls off that the X-34A is flying at its highest speed. At the end of the flight, the X-34A will fall to the ocean.

The X-34A was flown the first time in 2001, but the rocket booster failed. However it failed due to the Pegasus rocket booster lost control during flight. NASA decided to try the flight again on March 27, 2004. To everyone's delight, the test flight went well, breaking the world speed record by flying at over mach 7 (about 2,382.03 m / s). NASA is planning on doing another flight sometime during 2004.

Sources:
http://en.wikipedia.org/wiki/Boeing_X-43
http://www.arstechnica.com
http://www.nasa.gov/missions/research/x43-main.html