Editing Fireflash (section)

===Pink Hawk and Blue Sky===
It was soon realized that the all-aspect capability of Red Hawk was beyond the [[state of the art]] and a simpler weapon would be needed in the interim. In 1949, the RAE developed a watered-down specification they called "Pink Hawk" that called for a tail-chase attack and was intended to target piston-engined bombers. The Pink Hawk nickname was soon replaced with the official rainbow code, "Blue Sky".{{sfn|Gibson|Buttler|2007|p=31}} The Red Hawk project continued as well, but only briefly before its specifications were relaxed as well; in November 1951 the Air Staff issued OR.1117, given the code "Blue Jay", for an [[infrared seeking]] design which became Firestreak.{{sfn|Gibson|Buttler|2007|p=33}}{{sfn|Twigge|1993|p=163}}

Fairey Aviation won the contract to develop Blue Sky, which they referred to internally as Project 5. Like the original Little Ben, Project 5 called for a beam riding missile able to be launched from the rear aspect within a 15° cone.{{sfn|Gibson|Buttler|2007|p=31}} Wartime German research suggested that the rocket exhaust would [[ionize]] the air behind the missile and make it difficult to receive the radar signal, so Fairey based their design on the original Red Hawk layout using separate boosters that fell away during flight, leaving the signal clear while the unpowered "dart" continued on to the target. In place of the original four RP-3 rockets, two custom-designed "Stork" rockets were used.{{sfn|Gibson|Buttler|2007|p=32}} The two solid-fuel motors were connected to the dart about mid-way along the fuselage. The rocket nozzles were canted slightly to spin the missile assembly on launch, evening out any asymmetries in the thrust. When the boosters are empty, a small [[cordite]] charge separates them, leaving the dart to carry on towards the target.{{sfn|Flight|1957|p=227}}

Development of Blue Sky was aided by ongoing projects at Fairey in rocket propulsion that were being used to support the development of the [[Fairey Delta 2]] [[supersonic]] aircraft. This involved launching scale models of the proposed design using a locally designed [[liquid-fuel rocket]] engine, Beta 2. This also required the development of a complex multi-channel telemetry system that proved invaluable during the development of Blue Sky.{{sfn|Flight|1957|p=223}}