Because of war requirements in Iraq and Afghanistan, where coalition air forces could operate with little threat from the ground, the Air Force had poured funding into ISR collectors without stealthy characteristics such as the Beechcraft King Air-based MC‑12W Project Liberty and Blue Devil 1 intel platforms.
“For a decade now we have built the most incredible permissive ISR capacity and capability that anybody has ever seen,” Air Combat Command’s chief, Gen. Michael Hostage, said in September. “We are being forced to build a capacity [with the Reaper] I know I can’t sustain, and I know I don’t need based on the national strategy,” which calls for operating in heavily defended airspace, as well. He says Pentagon officials are sorting through what is needed to handle the more challenging threats. “We are talking about the entire ISR construct—how much in permissive, how much in contested and how much in denied” is needed.
Not since the Mach 3 SR-71 program ended in 1998 has the Pentagon been able to overfly targets in hostile airspace to collect intelligence. The proliferation of longer-range and integrated air-defense systems, coupled with its high operating cost, banished the Blackbird to museums. And in 1999, the Pentagon terminated the RQ-3 DarkStar UAS, a potential successor under development by Lockheed Martin and Boeing as a stealthy adjunct to Northrop Grumman’s RQ-4 Global Hawk, after it encountered flight-stability problems. These developments left unanswered a Pentagon Joint Requirements Oversight Council mission-need statement for an aircraft capable of operating in defended airspace for long periods.
Though satellites are capable of peering behind borders, they lack the persistence and flexibility of aircraft. Satellites are limited by slant ranges, a problem that aircraft can mitigate by altering their flight paths. Also, adversaries can predict when a spacecraft will fly overhead and adjust their operations accordingly.
High-speed platforms continue to be evaluated, such as Lockheed Martin’s hypersonic SR-72 concept (AW&ST Nov. 4, p. 18), but planners leery of acquisition foul-ups and higher-risk technology opted for stealth in order to field a system as soon as 2015.
The expectation that the RQ-180 will be fielded soon has helped to cement support for the Air Force’s abrupt change of heart on the Northrop Grumman Global Hawk high-altitude, long-endurance UAS—once the centerpiece for the service’s ISR development plans. The Block 30 Global Hawk was eyed as a replacement for the manned U-2 for stand-off ISR collection, in which aircraft just loiter outside hostile airspace peering into enemy territory to gather images and signals. Though not able to fly as high (50,000-60,000 ft. versus the U-2’s 70,000 ft.-plus), the Global Hawk could loiter for a day or longer and not expose pilots to the health hazards of prolonged missions at extreme altitudes, a problem during long flights supporting operations over Afghanistan.
Despite deeming Global Hawk critical to national security in 2011, the Air Force less than a year later proposed terminating the Block 30 version, citing the high operating cost it had once defended. The Air Force also cited lackluster performance of the Block 30’s electro-optical and radar-sensor suite, despite earlier assertions that these issues were manageable (AW&ST June 13, 2011, p. 35).
Now the more advanced, stealthy RQ-180, capable of penetrating an adversary’s airspace, has superseded the Global Hawk. The Air Force is now standing behind the U-2, with some cockpit and sensor upgrades, as its workhorse stand-off intelligence collector, with the RQ-180 poised to take on the penetrating mission.
In a high-level roles-and-missions trade, the Air Force assumed authority for developing a stealthier, longer-range, land-based UAS capable of penetrating the most defended airspace, guarded by advanced surface-to-air missiles and jammers. Meanwhile, the Navy, is mired in a debate over how stealthy to make its Uclass air vehicle when a high degree of stealth would push costs higher. With the Air Force operating the RQ-180, the Navy would have the option to cut its costs on Uclass.