Washington (CNN) The U.S. Air Force aims to develop an unmanned flying weapon by 2023 that would travel at least five times the speed of sound and might transform the nature of warfare.

"The key thing is, hypersonics go really fast," outgoing Air Force chief scientist Mica Endsley told CNN Thursday, after announcing the target date for the new aircraft last week.

The Pentagon has been experimenting with unmanned hypersonic aircraft for years, launching them from bombers over the Pacific with limited success.

For a vehicle to be considered hypersonic, it must travel at least at Mach 5 -- five times the speed of sound, or about 3,800 mph. That's fast enough to travel across the U.S. in around 30 minutes.

Air Force Maj. Gen. Thomas Masiello last year called hypersonic technology a potential "game-changer" that will transform the nature of warfare.

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