When the original definition of Tier III as a large, ultralong range, stealth, penetrating UAV was developed in 1993, it was made to mirror an ongoing special access Air Force program. Similar in size and price tag to the Northrop B-2 manned bomber, Lockheed Martin Skunk Works' Quartz UAV was canceled soon after its Cold War justification evaporated, but not before $1 billion had been spent on it. Quietly, however, Lockheed continued working on a scaled-down version of it, called DarkStar.

Meanwhile, DARPA keyed on shortfalls in intelligence capabilities identified from the Gulf War and its previous experience with HALSOL, Condor, and other programs to initiate the High-Altitude Endurance (HAE) reconnaissance UAV program in April 1994 as a way to meet some of the requirements for the Tier III UAV. When the Office of the Secretary of Defense (OSD) "invented" ACTDs later that same year, the HAE UAV program was designated as one of the initial ACTDs. Five designs, from Loral, Northrop Grumman, Orbital Sciences, Raytheon, and Teledyne Ryan Aeronautical (TRA), were initially evaluated, with the TRA Global Hawk design being selected in May 1995. But Global Hawk was a conventional aircraft, designed to stand off from hostile airspace while collecting intelligence. Lacking the stealthy penetrating capability envisioned for Tier III, it was labeled "Tier II+." To fulfill the Tier III requirement, it was combined in 1995 with the previously under development DarkStar stealth reconnaissance UAV into one joint HAE UAV program. This dual aircraft ACTD...