Sierra Nevada Corporation has won a U.S. Army contract to serve as the lead system integrator for the service’s future long-range spy plane.

The award for the High Accuracy Detection and Exploitation System, or HADES, integration work covers a 12-year period worth $93.5 million initially and potentially up to $994.3 million, the Army announced Thursday.

Choosing a lead integrator is a major step in the service’s effort to overhaul existing fixed-wing aircraft that perform intelligence, surveillance and reconnaissance missions. The service plans to retire roughly 70 aircraft – its entire ISR fleet – as it brings on the HADES aircraft that will be able to rapidly deploy and provide deep-sending capabilities.

“HADES is the centerpiece of the Army’s long-promised aerial ISR transformation strategy,” Lt. Gen. Anthony Hale, deputy chief of staff for Army intelligence (G-2), said in a statement announcing the deal. “HADES allows the Army to fly higher, faster and farther, which directly impacts our ability to see and sense deeper, delivering an organic capability in line with the Secretary of the Army’s number-one operational imperative – deep sensing.”

For the first time, the Army is using a large-cabin business jet – the Bombardier Global 6500 – to serve as the airframe for the spy plane. The service awarded Bombardier a contract in December for one aircraft, with an option to buy two more over a three-year period.

A L3Harris Technologies, MAG Aerospace and Leidos team was competing against Sierra Nevada for the integration contract. All four companies are involved in ISR fixed-wing prototype efforts with the Army.

The Army has spent more than five years assessing ISR fixed-wing prototypes using high-speed jets to inform the HADES program. It began with the deployment of Artemis – or Airborne Reconnaissance and Target Exploitation Multi-mission System – which has flown in the European theater near the Ukrainian border. Leidos built Artemis using a Bombardier Challenger 650 jet.

Then the service deployed Ares – or Airborne Reconnaissance and Electronic Warfare System – to the Pacific region in April 2022. L3Harris built the aircraft using a Bombardier Global Express 6500 jet.

Combined, Artemis and Ares had flown more than 1,000 sorties by April this year, according to Andrew Evans, who leads the Army’s ISR Task Force. They fly roughly 10-hour missions and average 20 sorties a month, he added.

The Army is also preparing to take on four more prototypes that will inform the requirements for the HADES program. The service chose a pair of companies to deliver two jets each with spy technologies to advance long-range targeting plans.

MAG Aerospace and L3Harris will outfit a Global 6500 with ISR sensors for the Army’s radar-focused Athena-R effort.

And Sierra Nevada is providing its RAPCON-X, based on a converted Bombardier business jet, for the service’s signals intelligence-focused Athena-S project.

Now that the Army has picked a team to integrate sensors onto the jet, the process will take 18 months before the aircraft can deploy for a user assessment, the Army has estimated. That assessment moves the aircraft from a controlled test environment in the United States to operational environments to stress test the systems.

The Army will deploy HADES for a limited period of time and then start building more aircraft as the early prototype remains deployed.

The service plans to field 14 HADES aircraft by 2035, according to a slide Maj. Gen. Wally Rugen, then-director of Army aviation, displayed during a speech at the Army Aviation Association of America’s annual conference in Denver in April.

While industry officials said they anticipate the Army will continue to award the same team subsequent contracts to build all of the HADES aircraft, Andrew Evans, who leads the Army’s ISR Task Force, noted earlier this year that “the guidance to our acquisition teammates was to ensure that we give ourselves as much flexibility as possible in the process.”

Using 70 “very capable” Beechcraft King Air and De Havilland Canada Dash-8 aircraft, the Army, “has done some enormous and powerful work in support of the wars in both Iraq and Afghanistan” Evans said. But the existing fleet won’t be able to fulfill long-range missions off the coast of China — which the U.S. government considers its top threat — “or really almost any other place in the world if you’re talking about extended geographic ranges with limited basing and access,” he added.