DARPA Announces Successful Scramjet Hypersonic Missile Test

Artist's concept of HAWC scramjet
Credit: Raytheon

A Raytheon-built, scramjet-powered, hypersonic cruise missile completed a free flight test last week, recording the first successful test of an air-breathing U.S. vehicle over Mach 5 since May 2013. 

“This test proves we can deliver the first operational hypersonic scramjet, providing a significant increase in warfighting capabilities,” said Colin Whelan, Raytheon’s vice president of Advanced Technology.

The test by DARPA’s Hypersonic Air-breathings Weapon Concept is a key step on path to fielding a follow-on hypersonic cruise missile by the U.S. and Australian air forces later in this decade. 

“This brings us one step closer to transitioning HAWC to a program of record that offers next-generation capability to the U.S. military,” said Andrew Koedler, DARPA’s HAWC program manager. 

The goal of the test was to complete several tasks, including integration with the Boeing B-52 launch aircraft, separation from the aircraft, booster ignition, booster separation, scramjet ignition and cruise flight. 

“All primary test objectives were met,” DARPA said. 

The Raytheon vehicle, which includes a Northrop Grumman-designed scramjet engine, is the first successful, air-launched, hypersonic missile test in over eight years. The Air Force Research Laboratory X-51, a Boeing/Aerojet Rocketdyne collaboration, achieved a top speed of Mach 5.1 on May 1, 2013.

DARPA launched the HAWC program three years later, choosing two competing teams—Raytheon/Northrop Grumman and Lockheed Martin/Aerojet—to demonstrate different designs for a scramjet-powered cruise missile by the end of 2019, but the program has been delayed by nearly two years. 

The Lockheed design was set to enter testing first, but encountered at least two reported setbacks in attempted tests. DARPA has announced no other successful hypersonic flight tests. 

“HAWC’s successful free flight test is the culmination of years of successful government and industry partnership, where a single, purpose-driven team accomplished an extremely challenging goal through intense collaboration,” Knoedler said. 

Raytheon, Lockheed and Boeing have been chosen to compete for a follow-on hypersonic cruise missile. All three companies won awards to participate in the design phase of the Southern Cross Integrated Flight Research Experiment, which will culminate in a flight test in 2024 on a Royal Australian Air Force F/A-18F. Likewise, the U.S. Air Force plans to launch the Hypersonic Attack Cruise Missile program in 2022 to field a new weapon within five years. 

Steve Trimble

Steve covers military aviation, missiles and space for the Aviation Week Network, based in Washington DC.