Hypersonics—missiles that travel at five times the speed of sound and thought to be impervious to just about any air defense capabilities that exist—are expected to be hugely important as the U.S. military prepared for great power competition against Russia or China.

The United States’ hypersonic program has shaved five years off of the fielding time through an inter-departmental approach that took successful components from the Army and Navy and the Air Force, Air Force Secretary Heather Wilson said at an event at the Center for Strategic and International Studies.

“The Army and the Navy had come up with a shell they were able to get to hypersonic speeds five times the speed of sound and maneuver,” she said. “Ours didn’t work, but what we have is rocket engines that are better than the ones that they have developed and so we got our engineers working together.”

“We have a … Navy funded Army tested shell of a weapon with an Air Force rocket motor that’s going to go on it,” she said. “We’re going to drop it off an aircraft. You guys are going to put it on a ship and they’re going to launch it from the ground and by working together we stripped five years out of the the fielding time.”