The 2006 Quadrennial Defense Review (QDR) identified four key national security challenges of the early 21st century. These four challenges are: defending the homeland in depth; fighting the Long War against radical extremists and defeating terrorist networks; preventing state and non-state actors from acquiring or using weapons of mass destruction; and hedging against the rise of a power or powers capable of competing with the United States militarily.
After a thorough assessment of the current program of record, the Secretary of Defense concluded that these emerging challenges would demand future joint air platforms with greater range (independent reach), greater persistence (ability to loiter over the target area), improved stealth (ability to survive in contested airspace), and improved networking (ability to operate as part of a joint multidimensional network). Consistent with this thinking, the final Report of the 2006 QDR directed the Department of the Navy (DoN) to “develop an unmanned longer-range carrier-based aircraft capable of being air-refueled to provide greater standoff capability, to expand payload and launch options, and to increase naval reach and persistence.” In other words, the Secretary of Defense directed the Navy to field a low-observable unmanned combat air system (UCAS) that is capable of operating safely off of a carrier deck, and over longer combat ranges than contemporary manned carrier-based aircraft.
The logic supporting accelerated development of a longer-range, carrier-based UCAS is straight-forward. Using manned aircraft, current carrier air wings are best suited for striking targets at ranges between 200 and 450 nautical miles (nm) from their carriers. At the same time, due primarily to the limits of aircrew endurance, these aircraft lack persistence. That is to say, they are generally limited to missions no more than ten hours long, and they more typically fly missions that last only a few hours. Therefore, US carrier air wings can maintain a persistent 24-hour-a-day presence over the battlefield only by massing several carriers. However, emerging national security challenges—including defending the homeland in depth, defeating global terrorist networks, operating in a world with more nuclear-armed regional powers, and hedging against the appearance of new anti-access/area-denial networks—will likely require future carrier task forces to stand off and fight from far greater distances than in the past, and to maintain a far more persistent presence over future battlefields. Moreover, when under constant threat of guided weapons attack, carriers will need to operate dispersed and mass their aircraft over targets from widely distributed operating areas. Under these circumstances, a carrier-based UCAS with an unrefueled combat radius of 1,500 nm or more and unconstrained by pilot physiology offers a significant boost in carrier combat capability. Indeed, with aerial refueling, a UCAS would be able to stay airborne for 50 to 100 hours—five to ten times longer than a manned aircraft. With multiple aerial refuelings, a UCAS could establish persistent surveillance-strike combat air patrols at ranges well beyond 3,000 nm, and could strike fixed targets at even longer ranges. Such extended reach and persistence would allow a dispersed aircraft carrier force to exert combat power over an enormous area.