Hypersonic missiles are a priority for the U.S. military because they are so difficult to defend against—they’re just too fast for today’s anti-aircraft and anti-missile defense systems to counter—and because the country’s biggest geopolitical rivals are steaming ahead.

China said last year that it was almost ready to demonstrate its own hypersonic weapons, and Russia claims that it too has conducted successful tests of a hypersonic missile that can carry nuclear or conventional warheads.

According to a Pentagon statement, Lockheed Martin’s development of the conventional strike weapons will take place at its Huntsville, Ala. facilities.

Three companies had bid for the project. The Pentagon didn’t identify them but, as FlightGlobal notes, only four companies were deemed acceptable bidders when the tender was opened: Lockheed Martin, Boeing (BA), Northrop Grumman (NOC) and Raytheon Missile Systems.

Boeing previously won a contract for an unmanned hypersonic scramjet called the X-51 Waverider, which the Air Force used for experiments between 2010 and 2013. That craft’s last test saw it reach a top speed of Mach 5.1, which just qualified it as hypersonic.

Boeing, the U.S. Air Force Research Laboratory and others conducted tests of an experimental hypersonic vehicle in Australia last year.

Meanwhile, Lockheed Martin is currently developing a hypersonic unmanned plane called the SR-72, or “son of the Blackbird.” The SR-72 is designed to fly at speeds up to Mach 6 (so, six times the speed of sound,) and CEO Marillyn Hewson claimed last month that it “could forever change our ability to deter and respond to conflict, allowing warfighters to quickly address threats before an adversary may have time to react.”