The 2013 test flight, which wound up being the longest air-breathing hypersonic flight ever, wrapped up a $300 million technology demonstration program beginning in 2004, Air Force officials said.
A B-52H Stratofortress carried the X-51A on its wing before it was released at 50,000 feet and accelerated up to Mach 4.8 in 26 seconds. As the scramjet climbed to 60,000 feet it accelerated to Mach 5.1.
The X-51 was also able to send back data before crashing into the ocean -- the kind of information now being used by scientists to engineer a more complete hypersonic vehicle.
"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," according to an Air Force statement at the time. "At impact, 370 seconds of data were collected from the experiment."
This Air Force the next-generation effort is not merely aimed at creating another scramjet but rather engineering a much more comprehensive hypersonic air vehicle, service scientists have explained.
Hypersonic flight requires technology designed to enable materials that can operate at the very high temperatures created by hypersonic speeds. They need guidance systems able to function as those speeds as well, Air Force officials have said.
The new air vehicle effort will progress alongside an Air Force hypersonic weapons program. While today's cruise missiles travel at speeds up to 600 miles per hour, hypersonic weapons will be able to reach speeds of Mach 5 to Mach 10, Air Force officials said.
The new air vehicle could be used to transport sensors, equipment or weaponry in the future, depending upon how the technology develops.
Also, Pentagon officials have said that hypersonic aircraft are expected to be much less expensive than traditional turbine engines because they require fewer parts.
For example, senior Air Force officials have said that hypersonic flight could speed up a five- hour flight from New York to Los Angeles to about 30 minutes. That being said, the speed of acceleration required for hypersonic flight may preclude or at least challenge the scientific possibility of humans being able to travel at that speed – a question that has yet to be fully determined.
This first appeared in Scout Warrior here.
Image Credit: Reuters.