WASHINGTON — As the U.S. Air Force embarks on a new effort to field a replacement for the MQ-9 Reaper drone, multiple defense companies are stepping up with new, long-range, stealthy design concepts for the emerging MQ-Next competition.

On Sept. 11, Northrop Grumman and Lockheed Martin released renderings of their respective offerings for the Air Force’s MQ-Next program. Northrop made public its swarming SG-2 concept, and Lockheed announced its flying-wing design.

General Atomics put out a concept drawing of a next-generation uncrewed aerial system on Sept. 14 to correspond with the first day of the Air Force Association’s Air, Space and Cyber Conference.

For the past two decades, the Air Force has relied on the MQ-1 Predator and then the MQ-9 Reaper — both made by General Atomics — as its workhorse drones for surveillance and strike missions in the Middle East.

But as more commercial drone makers enter the fray, it may become more economical and effective to operate a family of UAVs, with some built for high-end penetrating strike and reconnaissance missions, and others for low-end surveillance from commercial off-the-shelf manufacturers, said Will Roper, the Air Force’s top acquisition official.

“You might make the case that the Department [of the Air Force] needs both,” he said during a Sept. 15 roundtable with reporters. “But I wanted to give our team time to discuss with industry options that exist on both sides of that divide. We’ve got a lot of interesting responses, and I’m in discussions right now with the operational side of the Air Force about what they think the requirement is going to be.”

The Air Force issued a request for information to industry on June 3, seeking market research on available technologies as well as conceptual designs.

Boeing and Kratos each confirmed they responded to the request for information but have not released concept art for their potential offerings. General Atomics, Lockheed and Northrop have begun to shed light on their respective designs.

Northrop’s flying-wing design bears a close resemblance to the X-47B the company designed for the Navy, including using the same Distributed Autonomy/Responsive Control flight management system, which allows for operators to task multiple drones to fly autonomously according to parameters set by the user.

However, the aircraft in the rendering is just one potential concept that Northrop could develop for the MQ-Next family of systems, said Richard Sullivan, the company’s vice president of program management.

“The customer didn’t really give us strict requirements. We know that the [National Defense Strategy] scenario calls out environments with a pretty significant threat scenario. And so, what would we do to mitigate those?” he said. “We looked at those things, and we came up with a family of concepts … trying to solve the problem across the landscape in terms of the ranges, the threats and the costs.”

The General Atomics concept features a stealthy, long-winged, jet-powered air vehicle — a departure from the turboprop-powered MQ-9 Reaper. Dave Alexander, president of General Atomics Aeronautical Systems, told Defense News that the aircraft’s survivability and endurance, which is “significantly longer” than the Reaper, will be defining characteristics for the company’s offering.

Alexander also pointed to internal investments made by the company’s aeronautics division and its Electromagnetic Systems Group on advanced propulsion systems, though he declined to say more about potential engine advancements.

Keeping costs down will also be an important factor, he said. “Some platforms that get up to super high costs, even though they’re unmanned — you can’t afford to lose them. So they’re not attrition-tolerant, and we want to hang on to that piece of it.”

Lockheed Martin’s operational analysis has found that an optimal-force mix of drones will require high-end aircraft and low-cost, expendable systems that can operate in swarms, according to Jacob Johnson, the company’s unmanned aerial systems program manager.

The company’s next-generation UAS concept art features a tailless, stealthy, flying-wing design geared toward the high-end fight, although Johnson said Lockheed may put forward less exquisite systems depending on the Air Force’s final requirements.

“Over the last few years, with a lot of the [drone] shootdowns across the globe, one of the trends that I think is hard to ignore is what used to be considered permissive airspace. [It] is becoming increasingly contested,” he said. “Survivability is really the key to almost any mission, and I think that trend is going to continue into the future.”

However, survivability alone will not be enough, Johnson said. The Air Force has made clear that any future air system must plug into the service’s Advanced Battle Management System and export data across that system. Lockheed also plans to develop the drone using digital engineering to lower the total cost.