Artemis, named for the Greek goddess of the hunt, was an early

air-to-air missile An air-to-air missile (AAM) is a missile fired from an aircraft for the purpose of destroying another aircraft (including unmanned aircraft such as cruise missiles). AAMs are typically powered by one or more rocket motors, usually solid-fuel roc ...

project carried out by the

Royal Aircraft Establishment The Royal Aircraft Establishment (RAE) was a British research establishment, known by several different names during its history, that eventually came under the aegis of the Ministry of Defence (United Kingdom), UK Ministry of Defence (MoD), bef ...

(RAE) beginning in late 1943. The missile was intended for radar-equipped

night fighter A night fighter (later known as all-weather fighter or all-weather interceptor post-Second World War) is a largely historical term for a fighter aircraft, fighter or interceptor aircraft adapted or designed for effective use at night, during pe ...

s like the

Bristol Beaufighter The Bristol Type 156 Beaufighter (often called the Beau) is a British multi-role aircraft developed during the Second World War by the Bristol Aeroplane Company. It was originally conceived as a heavy fighter variant of the Bristol Beaufor ...

, which would track the target on their

AI Mk. IV radar Radar, Aircraft Interception, Mark IV (AI Mk. IV), also produced in the USA as SCR-540, was the world's first operational air-to-air radar system. Early Mk. III units appeared in July 1940 on converted Bristol Blenheim light bombers, while t ...

and then fire at a set range, with the missile homing on the signal of the AI radar being reflected off the target. The concept for Artemis led from an earlier project,

Spaniel A spaniel is a Dog type, type of gun dog. Spaniels were especially bred to flush game out of denser brush. By the late 17th century, spaniels had been specialized into water and land breeds. The extinct English Water Spaniel was used to retriev ...

, a

surface-to-air missile A surface-to-air missile (SAM), also known as a ground-to-air missile (GTAM) or surface-to-air guided weapon (SAGW), is a missile designed to be launched from the ground or the sea to destroy aircraft or other missiles. It is one type of anti-ai ...

based on the

RP-3 The RP-3 (from Rocket Projectile 3 inch) was a British air-to-ground rocket (weapon), rocket projectile introduced during the Second World War. The "3 inch" designation referred to the nominal diameter of the rocket motor tube. The use of a warhe ...

rocket motor. During development, a variation known as Air Spaniel was considered which would use

radio control Radio control (often abbreviated to RC) is the use of control signals transmitted by radio to remotely operate a device. Examples of simple radio control systems are garage door openers and keyless entry systems for vehicles, in which a small ha ...

for guidance. It was clear from early in the project that the six-second flight time would make such a system extremely difficult for the operator to correctly aim the missile in time, and the RAE decided that any such weapon had to be automatically guided. Artemis replaced the radio control system with a radio receiver to produce a simple form of

semi-active radar homing Semi-active radar homing (SARH) is a common type of missile guidance system, perhaps the most common type for longer-range air-to-air and surface-to-air missile systems. The name refers to the fact that the missile itself is only a passive dete ...

that would guide it on a curving path to its target. The project was cancelled when it was seen that the RP-3 based rocket had too short a range to keep the fighter outside the

bomber aircraft A bomber is a military combat aircraft that utilizes air-to-ground weaponry to drop bombs, launch torpedoes, or deploy air-launched cruise missiles. There are two major classifications of bomber: strategic and tactical. Strategic bombing is d ...

's defensive guns, especially during the period when the ''

Luftwaffe The Luftwaffe () was the aerial warfare, aerial-warfare branch of the before and during World War II. German Empire, Germany's military air arms during World War I, the of the Imperial German Army, Imperial Army and the of the Imperial Ge ...

'' was upgrading its aircraft with more powerful 20mm cannon. A larger design, Little Ben, took over development. There was a brief reprieve during the early stages of the

V-1 flying bomb The V-1 flying bomb ( "Vengeance Weapon 1") was an early cruise missile. Its official Reich Aviation Ministry () name was Fieseler Fi 103 and its suggestive name was (hellhound). It was also known to the Allies as the buzz bomb or doodlebug a ...

attacks in June 1944 as Artemis would allow slower aircraft to attack these weapons, but this was abandoned when radar-guided anti-aircraft guns and high-performance fighters proved effective.

Spaniel

Artemis ultimately traces its history to a 1941 project known as

. Spaniel was initially developed as a

(SAM) using a 3-inch Unrotated Projectile (UP-3) rocket with an optical guidance system using a

photocell Photodetectors, also called photosensors, are devices that detect light or other forms of electromagnetic radiation and convert it into an electrical signal. They are essential in a wide range of applications, from digital imaging and optical c ...

. When it was found that the UP-3 had too little performance to reach the targets while still having enough speed to guide itself using aerodynamic surfaces, two new concepts were developed. The first was to use rockets to guide the weapon instead of traditional aerodynamic surfaces, but it is unclear whether any actual development was carried out along these lines. The second was to mount the Spaniel on a

heavy fighter A heavy fighter is an historic category of fighter aircraft produced in the 1930s and 1940s, designed to carry heavier weapons or operate at longer ranges than light fighter aircraft. To achieve performance, most heavy fighters were twin-engine ...

like the

, at which point its limited range was no longer seen as a problem. As this concept was developed, a new seeker system using

command guidance Command guidance is a type of missile guidance in which a ground station or aircraft relay signals to a guided missile via radio control or through a wire connecting the missile to the launcher and tell the missile where to steer to intercept its ...

was developed. This would work in concert with new display systems for the

that would allow the radar operator in the aircraft to see both the missile and the target on a single display, and then use a

joystick A joystick, sometimes called a flight stick, is an input device consisting of a stick that pivots on a base and reports its angle or direction to the device it is controlling. Also known as the control column, it is the principal control devic ...

to guide the missile to the target as it flew. There were numerous concerns with the overall concept, ultimately leading to it being cancelled in 1942, as ''

'' attacks on the UK declined.

Artemis

The primary concern with the Spaniel was its short flight time, on the order of six seconds when fired at its ideal range of about . Flight Lieutenant Benson of the RAE had worked on Spaniel and felt that the operator would have too little time to accurately guide the weapon, especially given the first two seconds were unguided. He also pointed out systems were needed to keep the missile from spinning, which would make manual control impossible if the "up and down" axis continually rotated. These systems added significant cost and complexity. In 1943, Benson began the design of a new missile dedicated from the start as an air-to-air weapon. He proposed the name Artemis as "the Greek goddess of chase and death (may the Hun offer continual sacrifice)." The new design was created around the basic idea of allowing the missile to spin, using this as the primary method of stabilization and guidance. A small radio receiver tuned to the launch aircraft's AI Mk. IV radar was mounted in the nose of the missile. It had a highly directional antenna that made it sensitive only to one side of the missile fuselage. As the missile spun, it would periodically receive the radar signal as the antenna rotated past the target. Every time a signal was seen, a small plate would be flipped into the airstream, pulling the nose in that direction. The guidance system was not particularly powerful as it only actively turned the missile toward the target during the short periods when it was visible to the antenna. To increase the amount of time that was so, the nose section was mounted on a spindle and allowed to rotate independently of the rocket body. Small fins along the base of the nose caused it to spin at a rapid speed. Venting the rocket exhaust from a small hole at the rear of the missile was also considered as an alternate to the plate, providing more turning force. Because of the directionality of the antenna, it did not receive any signal when the target was dead ahead. This had the advantage of preventing the aerodynamic plate from being constantly deployed as it approached to closer range. It also meant the missile should not be launched with the fighter pointed directly at the target, they would have to be positioned so that the reflection of their radar would be visible to one side at launch. Artemis would then follow a curving path toward the target. Development was given a boost by the introduction of the

in 1944, but new radar-guided

anti-aircraft artillery Anti-aircraft warfare (AAW) is the counter to aerial warfare and includes "all measures designed to nullify or reduce the effectiveness of hostile air action".AAP-6 It encompasses surface-based, subsurface (Submarine#Armament, submarine-lau ...

and high-performance fighters proved to have the combination of features needed to defeat this threat. There were also concerns that the range of Artemis was too short to keep it out of the lethal range of new aircraft guns, which were moving to 20mm cannon and larger. Development ended in favour of a much larger and more developed weapon, Little Ben.

References

Citation

Bibliography

* {{cite book , first1=Chris , last1=Gibson , first2=Tony , last2=Buttler , title=British Secret Projects; Hypersonics, Ramjets and Missiles , publisher=Midland Publishing , date=2007 , isbn=9781857802580 Air-to-air missiles of the United Kingdom World War II guided missiles