Laser munition takes heat to moving targets
August 29, 2008
A few months earlier, it would have been hard for the military to take out the men they saw emplacing roadside bombs in Iraq’s Diyala province.
The men hopped into a truck on Aug. 12 and sped away from the scene, making them an all but impossible target for the Air Force’s workhorse bomb, the Joint Direct Attack Munition.
In May, though, the 332nd Air Expeditionary Wing aircraft received a new Laser Joint Direct Attack Munition that can target moving vehicles. The ground controller — called the Joint Terminal Air Controller — called in the attack, and F-16s from the 77th Expeditionary Fighter Squadron in Balad, Iraq, used the new bomb to destroy the truck before the insurgents could escape, said Maj. Jonathan Riley, the chief of public affairs for the 332nd AEW.
The LJDAM, which is also called Guided Bomb Unit-54, is the U.S. Air Force’s newest 500-pound precision weapon. It is equipped with a special targeting system that uses a combination of GPS and laser guidance to destroy moving targets.
The new LJDAM is similar to the old one, but has a laser-seeking head, Riley said. The GPS gets the bomb in the right area. The laser-seeking head then tracks the laser and feeds updates on the target’s location to the GPS as the bomb zeroes in on the target.
"It kind of gives us the best of both (bombs)," Riley said.
Laser-guided weapons have been in use since at least as far back as the Vietnam War. But they required someone — the pilot, another pilot or someone on the ground — to paint the target with a laser while the bomb traveled to its target, and that’s still the case.
The Air Force launched the JDAM program in 1991. The original JDAMs, which don’t follow lasers, use GPS coordinates to find their way to a target, making them easier to use and able to hit the target without someone directing it the entire way.
Because they must follow GPS coordinates, the older JDAMs were limited to stationary targets — meaning planes could direct them at buildings and bunkers but not vehicles.
The military already has Hellfire missiles to hit moving targets, but those are found more often on Apache helicopters and unmanned aircraft than on fighters, Riley said. The Air Force also fielded laser-guided Maverick missiles a year ago, but not every plane is equipped for them.
Planners determined in early 2007 that there was a critical need for a JDAM that could hit moving targets.
The Air Force completed the LJDAM’s development and testing cycle in less than 17 months. Aircraft from 332nd Air Expeditionary Wing first fielded the weapon in May.
Hellfires, which are half the size of a LJDAM, are more than capable of destroying an insurgent pickup truck. But the 500-pound GBU-54 is already on the small side for an airplane, and its heft could prove useful against tanks in future wars.
"(The Air Force is) thinking beyond just what we’re doing now," Riley said. "You’ll never know what we need to hit next."