As the expected air threat moved from medium-altitude strategic missions to low-altitude strikes, the fast reaction time and high manoeuvrability of the Rapier made it more effective than either of these weapons, replacing most of them by 1977.

[8] By the late 1950s, the British Army considered this threat considerable as new aircraft like the Sukhoi Su-7 became common and higher performance designs were in the pipeline.

For their immediate needs they purchased the new Bofors 40/L70, and for the longer term began a new missile development for a short-range, rapid-reaction weapon, known as the Light Anti-Aircraft (LAA) system.

The system was quite advanced, including automated search and track radars, a separate television camera for target identification, and eighteen missiles in two nine-round boxes.

A small antenna on the launcher trailer would communicate with the missile to bring it into alignment with the binoculars and then follow semi-active radar homing (SARH) from that point.

[11] During this time, Colin Baron and John Twinn at the Royal Aircraft Establishment were developing an optical semi-automatic command to line of sight (SACLOS) system.

The optical tracking system was so accurate that the missile almost always hit the target aircraft, so despite its small warhead and lack of a proximity fuze it almost guaranteed a kill.

Tigercat was similar to Rapier in basic concept, but based on older technologies and thus somewhat larger and heavier while offering less range and much slower speeds.

A complete Rapier targeting unit was placed in the center of the dome, and its guidance signals were captured and sent to the simulator to update the position of the missile.

The upper section also contains a separate missile tracking system that follows the operator's optics, based on a television camera optimized for the IR band.

The whole system and its crew are delivered by two Land Rovers designated the Fire Unit Truck (FUT) and the Detachment Support Vehicle (DSV).

To address this need, BAC started work on a separate radar guidance unit, primarily to improve foreign sales.

The Blindfire trailer carries its own generator unit, and is towed by a third Land Rover (a 12 V winch-equipped 101 FC) with the designation Tracking Radar Tractor (TRT).

With sales to Iran came the additional requirement for a fully-mobile version of Rapier to protect the Chieftain tanks being supplied on a UK MOD contract.

The initial proposal for the system was to simply mount the towed launcher, including its petrol generator set but minus its running gear, on the flatbed of the M548 carrier.

This included significant changes to armour the M548 vehicle, now designated RCM 748, and to incorporate the diesel-powered Coventry Climax H 30 engine to run the new generator set, and also as the auxiliary power unit.

After initially entering service at Towed FSB1 standard, with planar array radar and the 'Pointing Stick', the Tracked Rapiers were upgraded, with the latest version included a thermal-imaging enhanced tracker which enabled single vehicle 24-hour operation without the need for the Blindfire unit.

Laserfire thus represented a fairly major upgrade to the original optical system, allowing semi-automatic engagements, and greatly reducing operator skill and training requirements.

On the downside, Laserfire no longer has the optical system of the original, which served an important second duty by allowing the aircraft to be visually identified at long range.

In 1988 tests started on an improved warhead using a proximity fuze, in order to give Rapier capability against smaller targets that would be difficult to hit directly, notably high-speed remotely piloted vehicles.

Along with a further upgrade of the proximity fuze, the new missile incorporated (then) state-of-art technologies including: Von Karman supersonic aerodynamic profile; composite propellant, with a two-stage shaped burn and laminated body solid rocket motor; ceramic substrate surface mount PCBs; completely new electronic systems and software; both analogue and digital proprietary ASICs; highly ECM resistant front end and command link with redundant encoding; fully Digital Autopilot incorporating Kalman state filtering; inertial navigation comprising ring-laser roll and rate gyroscope; Kapton ribbon cabling.

By this time the Cold War was over and British air defence capabilities were significantly reduced, with fewer and smaller batteries, albeit every fire unit with Blindfire.

These included removing the role from the RAF Regiment as a measure to preserve Royal Artillery units in the face of significant cuts to the Army.

[citation needed] A number of years after the Shah was deposed in 1978, during informal contact with senior members of the Iranian army they indicated to a UK support organisation that they had continued to operate the initial batch of 30 launchers that had been delivered prior to the Shah's removal and that they had intercepted and destroyed a number of invading aircraft, significantly more than were engaged in the Falkland activities.

Their task was to provide air defence cover for a Harrier landing and re-fuelling pad built on the outskirts of Port San Carlos.

There were many sighting problems which prevented Rapier from operating efficiently, which led to it not being particularly effective in terms of number of 'kills'; but its presence acted as a deterrent, especially after the deployment of Blindfire systems around Port San Carlos.

The intermittent unserviceability of fire unit 32 alpha at Fitzroy was one of many factors that contributed to the success of the bombing of the RFA Sir Galahad.

The official history of the war states "Within the total, only five Argentine aircraft might have been shot down by Rapier, and, as originally noted by Ethell and Price, only one of these was certain, with two probables and two possibles.

"[23] The main problems were a lack of range, and the decision to omit a proximity fuze, an attribute which required the operator to strike the target aircraft directly with the missile.

[34] In July 2021 it was reported that Sky Sabre had started acceptance trials and training with the 7th Air Defence Group of the Royal Artillery.