Firestreak was the result of a series of projects begun with the OR.1056 Red Hawk missile, which called for an all-aspect seeker that could attack a target from any launch position.

When this proved too ambitious for the state of the art, another specification lacking the all-aspect requirement was released as Blue Sky, which briefly entered service as Fireflash the year before Firestreak.

In 1951 the Royal Aircraft Establishment (RAE), in charge of missile development, felt that infrared seeking had progressed to the point of reconsidering the Red Hawk requirement.

[1] Blue Jay developed as a fairly conventional-looking missile with cropped delta wings mounted just aft of the midpoint and small rectangular control surfaces in tandem towards the rear.

[3] The Magpie rocket motor took up only a small portion of the missile fuselage, placed between the actuators and the warhead, roughly centred under the mid-mounted wings.

[3] The lead telluride (PbTe) IR seeker was mounted under an eight-faceted conical arsenic trisulphide "pencil" nose and was cooled to −180 °C (−292.0 °F) to improve the signal-to-noise ratio.

The prodigious 19.3 pounds (8.8 kg) warhead had a 40 feet (12 m) lethal radius and was triggered either by the proximity fuzes or four contact fuses set on the front of the wings.

[6] The first airborne launch of Blue Jay took place in 1954 from a de Havilland Venom, the target drone - a Fairey Firefly - being destroyed.

[10] Looking for an improved weapon for the Operational Requirement F.155 interceptors, in 1955 the Air Ministry issued OR.1131 for an all-aspect design capability against enemy aircraft traveling at Mach 2.

[11][a] Work on Mk.4 was curtailed after 1956 as the RAE decided that the closing speeds of two Mach 2+ aircraft would be so rapid that the missile would have no chance to be launched while still within the range of its seeker.

[11] After the fallout of the 1957 Defence White Paper led to the cancellation of the F.155 and many other aircraft and missile projects, the English Electric Lightning was allowed to continue largely because development was almost complete.

The adoption of transistorized circuits in place of the former thermionic valves eliminated the need for cooling the electronics, as well as making the guidance section significantly smaller.

This still left more room that was used up by replacing the Magpie III with the new Linnet, which offered significantly higher performance and boosted the typical top speed of the missile from Mach 2.4 to 3.2 whilst almost doubling effective range to 7.5 miles (12.1 km).

This reduced its sensitivity compared to Violet Banner, lacking its true all-aspect ability, but further simplified the design and eliminated ground handling concerns.