11 remarkable images of NASA's record-breaking hypersonic aircraft X-43A

NASA's X-43A, also known as the Hyper X program, was a $230 million high-risk, high-payoff research program that led to a hypersonic flight in March of 2004.

How does the super fast plane work?

"A ramjet operates by subsonic combustion of fuel in a stream of air compressed by the forward speed of the aircraft itself, as opposed to a normal jet engine, in which the compressor section (the fan blades) compresses the air. Ramjets operate from about Mach 3 to Mach 6," stated a NASA release. 

"A scramjet (supersonic-combustion ramjet) is a ramjet engine in which the airflow through the engine remains supersonic. Scramjets powered vehicles are envisioned to operate at speeds up to at least Mach 15. Ground tests of scramjet combustors have shown this potential, but no flight tests have surpassed the Mach 9.6 X-43A flight."

The X43A's first flight attempt in June of 2001 failed as the booster rocket did not perform as planned.

However, this first attempt led to second and third trials that produced record-breaking flights. Mach 6.8 was achieved in March of 2004, and Mach 9.6 was reached in November of 2004, what would come to be the aircraft's final flight.

For the flights to take place, the stack was carried by a B-52B aircraft from NASA's Dryden Flight Research Center to a predetermined point over the Pacific Ocean, 50 miles west of the Southern California coast, and was released at 40,000 feet. At that moment, each stack was dropped from the B-52B, and the booster lifted the vehicles to their unique test altitude and speed.

This process proved so successful that the third and final flight reached speeds of nearly Mach 10, flying at approximately 7,000 mph at 110,000 feet in altitude and setting the current world speed record for an air-breathing vehicle.

Both the Mach 6.8 and Mach 9.6 accomplishments have been recognized by the Guinness World Records, which has listed the flights on their website and in the 2006 edition of their book of records. 

When the scramjet engine test was complete in each flight, the vehicle went into a high-speed maneuvering glide and collected nearly ten minutes of hypersonic aerodynamic data before splashing into the ocean, as planned. The vehicles were not recovered.

How did the X43A achieve such impressive flights?

Well, after the first flight failed, the scientists at NASA went back and did a lot of research, development, and engineering. 

"Wind tunnel tests were conducted to provide data to reduce atmospheric loads on the booster's control surfaces, more powerful booster fin actuators were added to overcome aerodynamic loads, and propellant was machined out of the Pegasus booster to enable launch at its normal launch altitude of 40,000 feet instead of 23,000 feet - as on the first flight - in order to reduce aerodynamic load," explained a NASA statement.

 Not a bad development for hypersonic flight!