DARPA's new hypersonic missiles could be a revolution in hypersonic technology — if successful.

The Need

The Defense Department’s secretive DARPA research and development group, responsible for some of the United States' most-secretive and cutting edge technology projects, is teaming up with Lockheed Martin to develop a new intermediate-range, ground-launched hypersonic weapon. The goal of the project, known as OpFires or Operational Fires, is to develop an “advanced booster capable of delivering a variety of payloads at a variety of ranges.”

In layman’s terms, OpFires would mate a new, variable-range hypersonic missile with mobile ground launch platforms that could engage high-value time-critical targets on land and at sea. Though the project does not sound particularly novel on paper, it’s actually an important revolution in hypersonic missile design. Here’s why.

Why It Matters

American hypersonic missile development is well-documented. By itself, a new, medium-range hypersonic missile would not necessarily be anything new or of particular note. What makes this project particularly difficult — and therefore within DARPA’s purview — is that this hypersonic rocket will be throttleable.

Rockets that run on solid fuel travel full steam ahead: once they’ve been ignited, they typically can’t be turned off or slowed down. Consequently, rockets can struggle to hit targets that are nearer than their maximum distance. Though theoretically possible, making a rocket speed down through the atmosphere with additional onboard weight in the form of unburned fuel can put massive amounts of stress on the rocket body, potentially causing the rocket to break up while in flight.

Making a rocket fly less than its maximum distance is difficult: it’s typically a bad thing if a rocket turns off while in flight. But to hit targets that are closer in or on the move, it could be necessary. And once the project is completed, it could be put to good use by the Marine Corps.

HIMARS and the Marine Corps’ New Mission

Although DARPA and Lockheed are developing OpFires for the U.S. Army, the project could also have big implications for the United States Marine Corps as well.

One mission that the Corps’ Reconnaissance Marines are training for would see Marines and Airmen perform an extremely rapid infiltration and exfiltration on enemy-held islands in the Pacific. Once secure, Air Force transports would land and unload a HIMARS long-range rocket artillery platform, which would then target enemy surface ships and make a quick getaway.

Though not currently equipped to fire hypersonic missiles, the Marine’s HIMARS system could in theory be adapted to quickly fire off hypersonic missiles at enemy ships, a capability that could give the United States an edge in a fast-paced Pacific conflict.

Postscript

Once design and flight testing are completed, the Lockheed-Martin-DARPA OpFires could be a game-changer, especially in the hands of American Marines. Still, it will be a few years until this technically challenging venture bears fruit. Lockheed estimates that components and subsystems will be tested later this year, with initial flight testing to begin in 2022.

Caleb Larson is a Defense Writer based in Europe. He holds a Master of Public Policy and covers U.S. and Russian security, European defense issues, and German politics and culture.