No Escape
A Eurofighter pilot spots his target, a faint glint against the skyline. A cockpit alarm verifies missile lock and within moments the missile has left the fighter and the distant glimmer has turned to flame.
We've all seen it done in films, but is aerial combat that simple?
"Locking onto a target is just the start," says Dr Neil Higson, engineer and technical consultant within Dstl's Missiles and Countermeasures Department. "The missile's journey from launch aircraft to target may only take seconds, but what happens in those few seconds is crucial to the outcome."
And it is this very journey to the so-called 'endgame' that Neil and his colleagues are most interested in. Using powerful software tools designed to simulate how a missile acts in flight the team can carefully study its effectiveness in one-on-one scenarios, how it can be improved upon and whether it matches the manufacturer's claims.
The team takes data from each element of a scenario, conditions at launch, the intervening 'fly-out' period, the 'terminal homing' phase, the manoeuvrability of the target for example, and then feeds it into the computer.
From there they are able to watch the missile react in real time, and manipulate the scenario at any given point, without incurring the costs of a real test firing.
The importance of such minute examination is explained by the fact that a direct hit is not always necessary to destroy the target, but the difference between a still-lethal miss and a near miss needs careful assessment.
To this end, various stages and systems used from launch to 'kill', taking anything from split seconds to minutes, can be isolated and assessed by the Dstl team:
Launch
"We use a mixture of expert opinion and industry supplied data to decide on the launch capabilities of each missile," says Neil. "We then add a range of conditions and combine all of this to form our launch specifications."
Mid-course guidance
Short-range missiles are usually locked on before launch, but others use a mid-course guidance system to find their target. Radar systems from the launch aircraft 'illuminate' and track the target while sending commands to the missile, guiding it by remote control to its destination.
Seeker search and acquisition/terminal guidance
In the final stages of flight, the missile becomes dependent on internal guidance systems to acquire the target - it can now 'see' the enemy and has no need for instructions from the launch aircraft.
"We can simulate many different types of seekers at this stage, the main ones being infra-red, radar and multi-spectral," says Neil. "We can test which seeker system would be most effective in a certain scenario."
"We can also include countermeasures (CMs) such as flares, chaff and radar jamming to simulate real combat - the missile is at its most vulnerable to CMs while in this terminal guidance phase, so we test it stringently at this point, incorporating things such as brake manoeuvres to see how the missile reacts."
Endgame
This is the critical part of the missile's journey and despite spanning just tens of milliseconds, this is the section that the Dstl team is most interested in.
"The guidance system is now redundant and the missile is effectively flying blind," says Neil. "Even if the missile hits its target it's not certain it will be destroyed. A hit doesn't necessarily mean a kill".
"Most missiles use proximity fuses. That means they are able to detonate at a certain distance from the aircraft. These fuses are crucial to the warhead's performance and are the subject of much research and development, both in Dstl and industry. We look into alternative sensors, processors and algorithms to increase lethality."
Once the warhead has detonated, further software is used to dissect the particular target down to its smallest components and simulate how the warhead fragments interact as they penetrate the aircraft and the more vulnerable areas inside.
The future
Much of the work behind the Dstl team's missile engagement modelling is for future perceived threats and scenarios and the biggest potential problem here is enemy counter-measures (CMs).
CMs have increased in complexity to combat new missile developments such as imaging seekers, so Dstl has to ensure that the UK stays one step ahead of the opposition.
At present, CMs, together with 'stealth' and increased warplane manoeuvrability, mean that an increasing 'miss distance' for air-to-air missiles may have to be tolerated, though new research is investigating how to restore the balance.
One option is new systems that can actually strike specific parts of the target, while another avenue is multi-role missiles for any platform, long or short range use, and ground attack or anti-aircraft deployment. This multi-role approach should deliver cost benefits too' but it has to pass the rigid virtual reality testing of the Dstl team.