Lockheed Skunkworks chief Neal Kasena tells us that a Mach 5-plus class aircraft is certainly possible by 2018—the previously rumored deadline for a “prompt global strike” system—but that wouldn’t quite meet the desire to hit global targets in under an hour. For a Mach 5-class vehicle, he says, the Skunkworks has looked at using hydrocarbon fuels in a two-engine system—one a turbine for takeoff, climb, and descent/landing, and scramjets for super-high-altitude cruise. For the ultimate one-hour requirement, new fuels and a different technology would be needed—nearly doubling speed to Mach 9-plus—but the solution probably wouldn’t be available until the mid-2020s.
The rate of building B-21 bombers would speed up if the fiscal 2026 defense budget passes. But it remains unclear how much capacity would be added, and whether the Air Force would simply build the bombers faster, or buy more.
