The U.S. Air Force’s future drone fighter is back in the air.

The XQ-58 Valkyrie on June 11, 2019 took off for its second test flight over Yuma, Arizona. The 29-feet-long, jet-powered drone “successfully completed all test objectives during a 71-minute flight,” the Air Force Research Laboratory announced.

The Valkyrie’s first flight took place in March 2019. The Air Force and California drone-maker Kratos plan to conduct five test sorties during this phase of the XQ-58’s development.

The Valkyrie is part of a wider Air Force effort to acquire fast, stealthy, armed drones that can fly and fight alongside manned fighters. 

While the Valkyrie program develops one type of wingman drone, the broader Skyborg program is working on the hardware and software for integrating manned and unmanned fighters.

A new version of the Air Force’s F-35A stealth fighter, as well as the heavily upgraded version of the F-15 that the flying branch hopes to acquire, both could function as flight leads for the service’s wingman drones, Will Roper, the Air Force’s top weapons-buyer, told Defense News reporter Valerie Insinna.

The Air Force is in discussions with Boeing and Lockheed respectively to modify their F-15EX and F-35A Block 4 fighters to accommodate the datalinks and processors from the Skyborg effort, Insinna reported.

Roper confirmed that the Air Force eventually will fold the subsonic XQ-58 into the Skyborg program. The Air Force plans to test wingman drones in 2019 and 2020 “with the hope of having an aircraft ready by 2023,” Insinna wrote.

Roper told Insinna that pairing manned fighters with drones could “open up the door for an entirely different way to do aerial combat.”

“For example, take a typical four-aircraft formation and replace it with an F-15EX and three Valkyries,” Insinna explained.

“We can take risk with some systems to keep others safer,” Roper said. “We can separate the sensor and the shooter. Right now they’re collocated on a single platform with a person in it. In the future, we can separate them out, put sensors ahead of shooters, put our manned systems behind the unmanned. There’s a whole playbook.”

Pilots and crew in manned planes and controllers on the ground both could direct the wingman drones. But the unmanned aerial vehicles themselves could end up being highly autonomous.

According to Kratos, the XQ-58’s capability "ranges from the low side of semi-autonomous (operator directed, autopilot stabilized) to the side of semi-autonomous (waypoint nav). The system includes standard interfaces to enable full autonomy capabilities."

The XQ-58's flight-testing signals an expansion of international efforts to develop UAVs that can fly and fight in mixed formations with manned warplanes.

Boeing's Australian subsidiary in February 2019 unveiled its so-called "Airpower Teaming System," a 38-foot-long, jet-powered drone that the company said could carry weapons and sensors and fly as far as 2,000 miles—all while being more affordable than a $100-million manned jet.

Boeing developed the new drone in cooperation with the Australian military. After further development, the Royal Australian Air Force could acquire the UAV to quickly and cheaply add firepower to its roughly 100-strong fighter fleet and six E-7 radar planes.

"The Boeing Airpower Teaming System is designed to team with a wide range of existing military aircraft from fighters to commercial derivative aircraft," said Ashlee Erwin, a Boeing spokesperson.

Beside Australia, China and Japan also are working on wingman drones. A mock-up or prototype of China's 30-feet-long Dark Sword drone first appeared in public in an undated photo that circulated on-line in mid-2018.

Japan revealed its own "Combat Support Unmanned Aircraft" wingman drone concept in a technology roadmap that Aviation Week first published in late 2016.

Wingman drones could change the way major air forces fight, according to Peter W. Singer, author of Wired for War. "The idea of a robot wingman is that it can keep pace with manned planes, but be tasked out for parts of the mission that you wouldn't send a human teammate to do.”

David Axe serves as Defense Editor of the National Interest. He is the author of the graphic novels  War Fix,War Is Boring and Machete Squad.