Art of the Possible

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.