February 1, 2011: During recent Chinese army training exercises, an official casually mentioned that Chinese troops were firing a GPS guided artillery shell. This would indicate that China now has such an advanced munition in service. The U.S. version of this weapon, Excalibur, has encountered formidable competition from other guided weapons. American and Canadian troops began using the Excalibur shell in Afghanistan since 2008. Four years ago, American troops began using Excalibur in Iraq.

This was timely, because Islamic warriors tend to use civilians as human shields, and that means you have to be precise when you go after the bad guys. The Excalibur shell enabled the artillery to take care of these chores. A typical situation has enemy gunmen holding out in one building of a walled compound or village. In nearby buildings, there are women and children. While killing the enemy is good, killing the civilians can be a very bad thing. Smart bombs should be able to fix this, except that sometimes one of the smaller smart bombs, the 228 kg  (500 pounder), has too much bang (127 kg/280 pounds of explosives).

A 155mm artillery shell should do the trick (only 9 kg/20 pounds of explosives each), but at long range (20 kilometers or more), some of these shells will hit the civilians. That's because at that range, an unguided 155mm shell can land up to 100-200 meters from where you aimed it. This is where Excalibur comes in handy. The GPS guided Excalibur shell falls within a ten meter circle (the middle of that circle being the "aim point") no matter what the range.

After a year of use in Iraq, the troops foud Excalibur invaluable for hitting just what you want to hit, and with a minimal amount of bang. Excalibur, being an artillery (which is controlled by the army) weapon, is easier to call in than a smart bomb (air force) attack. U.S. Army attack helicopters also have their Hellfire missiles, which provide a bit less bang than the Excalibur shell (and cost about the same). But while weather (especially sand storms) can interfere with helicopter operations, Excalibur is always ready to fire.

For most nations, the big drawback with Excalibur is cost (over $100,000 per shell). A "dumb" 155mm shell costs $300 or less, but when you take into account the civilian lives saved (and good will retained), it's a different story. Moreover, friendly troops can be closer to the target when Excalibur is used, meaning your infantry can get into the shelled target quicker, before any surviving enemy can get ready to shoot back.

The Excalibur shell is worth it in other ways. Ten 155mm shells (of any type, with their propellant and packaging) weigh about a ton. Ammo supply has always been a major problem with artillery, and Excalibur is the solution. With Excalibur, fewer 155mm shells have to be shipped thousands of miles, and looked after until they are used. One Excalibur shell can take out a target that would require 10-20 unguided shells.

Excalibur was developed in the United States, in cooperation with Swedish engineers, The Excalibur was originally supposed to cost under $50,000 each, and with more being produced, the per-shell price may eventually fall to the planned price. At one point, 150 Excaliburs were being produced each month, and the army wanted to double that. But then it was found that there were not as many situations calling for GPS precision 155mm shells as was originally thought. With all the Hellfire, JDAM and other smart bombs available, it turned out that there were actually few situations that required Excalibur. What really hurt the Excalibur use, and purchases, was the GPS guided 227mm MLRS rocket (GMLRS). The 309 kg (680 pound) rocket has more than twice the range of Excalibur and cost more than a third less. The larger GMLRS warhead was sometimes a factor, but that was rare.

The GMLRS rocket moves much more slowly, and this means the electronic components don't have to be as sturdy, and expensive. Developing electronics and control systems that fit inside a 155mm diameter shell, and survive being fired out of a cannon, proved more difficult than expected. That's why a GPS guided smart bomb only costs about $30,000, while the first hundred or so Excaliburs cost nearly ten times as much.

Developing smart artillery shells is risky. The U.S. Navy cancelled a project to develop a similar 127mm shell, and is now looking into adopting the Excalibur technology for a GPS guided 127mm shell that works. Smart shells are a nice idea, but getting from here to there is a risky and expensive process.

If China has their own GPS guided 155mm artillery shell, it is also, for them, a very expensive item. China has also developed several different GPS guided rockets.