Did the U.S. military miss its window of opportunity to beat out adversaries in hypersonics development?
That depends on what the U.S. chooses to build even as Russia and China are rapidly advancing the technology, according to the vice chairman of the Joint Chiefs of Staff.
"We have lost our technical advantage in hypersonics; we haven't lost the hypersonics fight," Air Force Gen. Paul Selva told reporters Tuesday during a roundtable discussion in Washington, D.C.
"China has made it a national program, so China's willing to spend tens to up to hundreds of billions to solve the problem of hypersonic flight, hypersonic target designation, and then ultimately engagement," he said.
The Defense Department has instead taken an approach that incorporates a "family of hypersonic systems that work without necessarily trying to close all the technology pieces on the front end," Selva said.
Hypersonic technology offers highly supersonic speeds of Mach 5 or above. But it presents two big problems: channeling the excess energy generated by the weapon and maintaining control at those speeds. Researchers are working to develop a hypersonic vehicle or weapon that is survivable and maneuverable.
How and when it strikes also matters.
"Closing the kill chain is something that will happen later in the development of the technology: It's either going to go after fixed targets, which is a relatively easy kill chain to close, [or] if it's going after moving targets, you're going to have to continue to maneuver it until it accomplishes an intercept, and that is a really tough kill-chain problem," Selva said.
The DoD is also weighing whether to involve human pilots in the equation.
"... A manned hypersonic capability out in the future is still something that is a question of, 'Can you scale hypersonics [to be] small, highly maneuverable, high G [force], sturdy machines to something you'd put a human in?' And I'm just not sure that one would invest the money to make that transition," Selva said.
Selva said three offices are pushing hypersonics research at the Pentagon.
"DARPA [Defense Advanced Research Projects Agency] is working on extremely advanced hypersonics research, and the Navy has a hypersonics program," he said. "The third one I won't reveal."