The tests are part of the long-running HIFiRE (Hypersonic International Flight Research Experimentation) program, whose first launch took place way back in 2009. They should help bring hypersonic flight to a "range of applications," according to HIFiRE partner BAE. That could easily include ultra-fast aircraft, but it's widely believed the focus here is on missiles and similar unmanned weapons. A hypersonic missile would fulfill the US military's goal of building a conventional weapon that can strike anywhere within an hour, and it would be virtually impossible to stop using existing missile defenses. In theory, enemy nations wouldn't dare attack if they knew they'd face certain retaliation within minutes.

Any real-world uses of hypersonic weapons are likely years away, but they might come sooner than you think. US Navy Admiral Harry Harris recently worried about keeping up with (or ahead of) of hypersonic weapon development by the Chinese and Russians. These latest tests signal that the US isn't just treating hypersonic weapons as theoretical exercises. It wants practical uses in a reasonable time frame -- if just to say that it's keeping up with its rivals.