Getting a jet in the air and up to a high speed and getting a jet from that high speed to high Mach speeds require two different engines, which requires some costly and annoying procedures. Currently, one jet will have to take another up to speed, allowing the engine designed for Mach speeds that's on the second jet to take it to the next level once its in the air. Requiring two planes is obviously not the most efficient thing in the world, so DARPA is hard at work on a solution.

That solution might just be the new Vulcan engine, "a propulsion system that combines a Constant Volume Combustion (CVC) engine and a full-scale turbine engine to accelerate a hypersonic jet to multiple Mach." The goal is to create a craft that can deliver a payload up to 9,000 nautical miles from the US in less than two hours, which is pretty insane. Lets get this thing in commercial airliners, OK DARPA?

Crave, via New Launches