Not many aircraft in military aviation history have been shrouded in mystery and conjured as much speculation as the SR-91 Aurora. First appearing in the 1980s, “Aurora” was listed in a black program spy plane request, and ever since, this mysterious airframe has remained cloaked in secrecy. It was an attempt by military engineers to come up with a hypersonic plane design that would clock over Mach 5.0; no other aircraft has been reported to do so.
The SR-91 Aurora entered public awareness through the Los Angeles Times and Aviation Week & Space Technology reports in the mid-1980s. All the reports made the point that “Aurora” had been included inadvertently in the budget for 1995, which the U.S. government had submitted for “black aircraft production,” insinuating a clandestine project with funding greater than nearly $1 billion for the B-2 Spirit. By 1986, funding for the black project had swelled to about $2.7 billion, according to a procurement document obtained by Aviation Week.
In the 1980s, with the world’s fastest plane, the SR-71 Blackbird, reaching the end of its service life, a replacement had to be taken into consideration. That very impressive flying machine was powered by Pratt & Whitney J58 engines and represented an early effort at stealth design that could break Mach 3.2. According to analysts, the U.S. was capable of fielding a Mach 5.0 airframe and probably did so with the SR-91 Aurora.
Over the years, several reports and sightings have been viewed as a confirmation of the existence of the Aurora. One such sighting was reported by an engineer in 1989 over the North Sea, which claimed that the Aurora was a triangular-shaped aircraft. However, considering the speed at which the aircraft is supposed to fly, such sightings do not seem very credible. When the Aurora was supposedly flying, the Air Force’s B-2 bomber and F-117 Nighthawk were operational and would have accounted for the sightings.
In 2000, Nic Outterside of the Aberdeen Press and Journal cited anonymous sources that RAF/USAF Machrihanish in Kintyre, Argyll, served as a base for Aurora airframes. The long runways would be suitable for high-altitude experimental aircraft. More evidence appeared in the form of an answer to a parliamentary question in 2006 which stated that the British Ministry of Defense had been told by the United States that the U.S. Air Force had plans to produce a Mach 4.0-6.0 supersonic airframe, though no evidence conclusively proved that such a project existed.
So-called “sky quakes” over Los Angeles, first observed in the early 1990s, have also been attributed to the Aurora. In 1993, Bill Sweetman of Jane’s Defense Weekly reported that U.S. Geological Survey seismologists had recorded tremors consistent with a sonic boom from a high-altitude supersonic aircraft. These tremors were not in line with any known aircraft, suggesting something faster and more advanced.
Though countless claims and sightings have been made, the SR-91 Aurora has not been confirmed by U.S. officials. If it does exist, it would shatter the Blackbird’s speed record into minute pieces, truly heralding a new era in hypersonic flight.
The SR-91 Aurora has seldom failed to impress the imagination of aircraft enthusiasts and military analysts. From fact to fiction, and through internet myth, Aurora is what aerospace ambition and the mysterious represent.