The XQ-58A Valkyrie, a jet-powered drone designed to fly alongside manned fighter jets and navigate autonomously, completed its first test flight Tuesday at Yuma Proving Grounds in Arizona, according to an Air Force announcement and video released Wednesday.

The flight test is a major step forward for an experimental “loyal wingman” concept that envisions small robotic drones accompanying fighter jets into combat, scouting ahead or absorbing enemy fire. Military experts have suggested such systems would be useful in a war between two rival nations, something that aligns with the Pentagon’s increasing focus on competing with China and Russia for military dominance.

The Pentagon has yet to commit to the idea. But the Air Force Research Laboratory is among several military agencies dabbling in such technology, partnering with a San Diego-based company called Kratos Defense and Security Solutions to develop the Valkyrie.

Chicago-based aerospace giant Boeing introduced its own “loyal wingman” prototype drone last month at a trade show in Australia, according to the trade publication Defense News. It expects its variant to achieve its first flight next year.

The Valkyrie has an estimated unit cost of $2 million to $3 million, something that is intended to give it a similar cost profile to the antiaircraft missiles that enemies would theoretically fire at it. And it is distinct from prevailing U.S. drone models such as the MQ-9 Reaper in that it is jet-powered and can fly at near-supersonic speeds, which could enable it to keep pace with an F-16 or F-35 fighter jet.

The Valkyrie “is the first example of a class of [drone] that is defined by low procurement and operating costs while providing game changing combat capability,” Air Force Research Lab program manager Doug Szczublewski said in a statement.

The test is also a major step forward for Kratos, the Valkyrie’s manufacturer. Kratos already does a steady business with the U.S. military for small drones the military uses for target practice in training exercises. And it has been trying to break into the much larger military fighter jet market that is dominated by Lockheed Martin, Boeing and Northrop Grumman.

Kratos chief executive Eric DeMarco said in a call with investors late last month that a successful initial flight test for the Valkyrie would be “one of the most significant milestones in Kratos’ history."

“We also see 2019 as the year that Kratos is established as the world leader in the high performance unmanned aerial drone system product class that we’re in, which we see as a multibillion-dollar opportunity for our company,” DeMarco said.

Clarification: The XQ-58A Valkyrie is designed to accompany fighter jets at “high-subsonic” speeds, not supersonic. This article has been updated.