Originally called "Super Bloodhound", Blue Envoy was to meetStage 1 3/4 of the Staged air defence plan. Blue Envoy was ramjet powered and intended to have a range of 150 miles with an impact range of 90 miles against a Mach 2 high altitude aircraft or guided bomb.
The planform was a double delta, with twist and steer being used to control the missile. Power was provided by a pair of BristolBRJ.811 18" ramjets, with a quartet of Borzoi boost motors providing the launch acceleration. Guidance was by mid course update with semi-active continuous wave terminal homing using the Type 87 Blue Anchor X-band Target Illumination Radar.
The warhead was to be a large HE / continuous rod device, with the intention of adding a nuclear warhead such asBlue Cat at a later date.
Blue Envoy was cancelled at the flight test stage in April 1957. The work done on Blue Envoy was not lost. The continuous wave guidance system and the improvements made to the BRJ.801 ramjets were applied to the Bloodhound I, producing Bloodhound II. This was a superior weapon and would be in RAF service until the 1990s.
The drawing shown at the left was compiled from descriptions and what little information has been published on Blue Envoy. To date that is about a single sentence.
Guided Weapons or Ramjets or Radar or Nuclear Weapons or Stages.