AA-39 Sunbeam

Type: Short-range AAM

Guidance: Infra-Red Imaging
Fusing: multidirectional laser proximity, impact
Powerplant: Solid-fuel rocket motor
Control: Latticed multi-surface aerodynamic control

Max speed: Mach 3.72
Range: 22km

Launch mass: 116kg
Warhead: 12.6kg blast/fragmentation

Diameter: 178mm
Wingspan: 494mm
Length: 2.93m

Producer: Prouqarl Ordnance Inc.
Unit Price: NS$ 395,000

Abstract
The AA-37 Clipper air-to-air missile was the Protean Commonwealth's primary short-range AAM for many years, but during the Loering conflict it became apparent that it no longer performed adequately in a modern combat situation. Pilots reported that the missile's outdated targeting software was too easily confused, making the Clipper highly susceptible to the towed decoys being deployed by their Sarocian adversaries and leaving Commonwealth pilots with unguided rockets and machine cannon as their only offensive options. Feeling that this was simply unacceptable, the Commonwealth Ministry of Defence immediately put out a brief for a new short-range AAM, stressing the importance of resistance to countermeasures. Several companies put forward designs, but it was Prouqarl Ordnance Inc who were awarded the contract for the AA-39 Sunbeam.

Guidance
The Sunbeam uses a cryogenically-cooled 16,384-element diffraction-compensated focal plane array to build an image with much greater resolution than previously seen in missiles with only a minimal increase in weight and complexity. The ability of this system to deliver greater resolution with similarly-sized arrays allows the Sunbeam to use lensing in the seeker head to give great off-boresight targeting, accurately tracking contacts up to 70^o from the missile's primary axis. The Sunbeam also uses procedural shape recognition algorithms to identify aircraft by the layout, and not just the magnitude, of their thermal signature. This gives the missile great resistance to conventional thermal countermeasures such as flares, because the missile will not be deceived unless the countermeasures are sufficient in number or magnitude that the aircraft's characteristic nose-wing-tail-exhaust shape cannot be discerned. It also eliminates much of the advantage of aircraft designed to have lower thermal signatures, because the missile targets them by shape as well as temperature, so lowering the temperature will not confuse it. The missile can be given a target by the parent aircraft's computer to lock on before launch, or can be fired without a lock, using its recognition capabilities to identify aircraft, eleminating friendly contacts by their IFF transponders and by cross-referencing against the missile's own internal database of Commonwealth aircraft signatures, and selecting a target based on hit probabilities.

Powerplant
The Sunbeam uses a dual-thrust solid-fuel rocket, in which the fuel density varies to vary the thrust during flight. The first stage delivers a fast burn to accelerate rapidly after launch, while the second stage is optimised for more efficient flight to get the maximum possible range out of the available fuel mass.