January10, 2007: The U.S. Army is testing a thermobaric (fuel air explosive) warhead for its GMLRS (officially the "GMLRS Unitary rocket") rockets. In the last year, U.S. Army artillery units in Iraq have been firing about ten GPS guided 227mm MLRS rockets a month in Iraq. When the GMLRS (Guided MLRS) first went into action, the troops realized that this was a near-perfect artillery weapon. There have been no reliability problems with the GMLRS, which has a range of 70 kilometers and, because of the GPS guidance, has the same accuracy at any range. Unguided rockets become less accurate the farther they go. The GMLRS is designed to put each rocket with in a 16 foot circle (the center of which is the GPS coordinates the rocket is programmed to go for). In nearly all cases, the GMLRS rocket appears to land less than ten feet from the aiming point.

What makes the GMLRS most useful is not just its accuracy, which is about the same as air force JDAM GPS guided smart bombs, but because the 200 pound GMLRS warhead produces a smaller bang than the smallest JDAM (500 pounds). When it comes to urban fighting, smaller is better. Less collateral damage, and your troops can be closer to the target when the explosion occurs. In Iraq, the 200 pound GMLRS warhead is just the right size for your average Iraqi building. The structure, and the bad guys within, are destroyed, and adjacent structures suffer minimal, or no, damage. For that reason, even some Iraqi politicians have come out in praise of the GMLRS.

The new thermobaric warhead operates by dispersing an inflammable mist, then igniting it. This produces an explosion that kills by sucking the oxygen out of the surrounding areas, as well as with blast. Fired into a large building, the thermobaric would kill more people inside, and do less damage to adjacent structures. Thermobaric warheads have been used with great success in shoulder fired rocket launchers.

In order to get more GMLRS, all new MLRS production is being switched to GMLRS, and a retrofit kit, that will turn unguided MLRS rockets into GMLRS, has been introduced. The army believes that GMLRS will remain the most useful smart weapon, even with the coming introduction of the hundred pound 155mm GPS guided Excalibur artillery shell, and the U.S. Air Force's 250 pound JDAM (the SDB, or small diameter bomb). Both of these weapons pack a smaller punch than the GMLRS, and that may be a drawback in some situations. Ground troops are certain that the GMLRS warhead is just right, at least in most cases. But the Excalibur and SDB will get a workout anyway, and they will probably prove useful, even if they have to compete with a thermobaric GMLRS.