Block tactics

Australian, UK and US aircraft could soon be protected against heat-seeking missile attack by a laser that ‘jams’ the incoming rocket’s infrared sensors.

The surface-to-air missile used in the al-Qaeda attack on an Israeli airliner taking off from Mombasa airport last year relied on heat-seeking technology. The missile was attracted to the heat given off by the aircraft’s engines. Although it missed its target, military and civilian aircraft could increasingly be at risk from such weapons.

At present flares are used to distract infrared sensors and chaff to confuse enemy radar. But military aircraft have a finite quantity of both. To counter infrared missiles the UK, Australia and the US are developing an alternative laser system, which would be used to project a heat signature on to the missile’s sensors at a safe distance from the target aircraft.

The Australian Department of Defence said that it has successfully tested the laser. Dr Nanda Nandagopal, director of the system science laboratory for its Defence Science and Technology Organisation’s infrared countermeasure laboratory in Edinburgh, south Australia, said: ‘Laser-based Directed InfraRed Counter Measure (DIRCM) jamming systems are at the leading edge of technology for the protection of aircraft engines against advanced air-to-air and surface-to-air infrared weapons.’

An aircraft might be fitted with more than one laser to cover targets approaching from above and below. These could be placed on the nose cone and the tail. But the researchers have also considered using a single laser. This would be split and carried by optical fibre to beam directors, again located at the tail and nose.

The solid-state laser will rely on a crystal or a glass-matrix structure to improve photon generation. However, the project is also examining gas and liquid alternatives. The next stage of the research is to improve the laser’s power, effectiveness, reliability and distribution by using optical fibre.

The jamming system will be fitted to the Royal Australian Air Force’s Airborne Early Warning and Control aircraft, which will enter service in 2007. The UK’s Ministry of Defence was unable to give a deployment date, but DIRCM participant company Northrop Grumman has stated that the US Air Force will use the laser on its C-130 and C-17 transport aircraft. The firm said the laser could protect rotary-wing aircraft and other fixed-wing types.