October 11,2008:  The U.S. Army is developing a second generation version of its Excalibur, 155mm, GPS guided artillery shell. This new model will reduce the cost per shell from about $85,000 each, to $50,000. Australia and Canada have also bought, and used, Excalibur in Afghanistan. U.S. troops use it there, and in Iraq. Sweden will receive Excalibur in two years.

The "B" version of Excalibur won't be available for four years, and will have inertial guidance, in addition to GPS. This means that, if GPS signals are jammed, the shell will still be very accurate (landing within about fifteen meters of the aim point, compared to five meters for GPS.) Inertial guidance has long been used as a back-up in GPS guided smart bombs (JDAM). The new version of Excalibur will also use new, cheaper and more reliable components. Currently, several thousand Excalibur shells are being produced each year, and that will continue to increase.

Excalibur comes in very handy when Islamic warriors use civilians as human shields. In those situations, 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 500 pounder, has too much bang (280 pounds of explosives).

A 155mm artillery shell should do the trick (only 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. This kind of accuracy enables the troops to take out the enemy with one shot, and unprecedented precision.

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. A "dumb" 155mm shell costs $300 or less, although 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 the Swedish firm Bofors. The Excalibur was originally supposed to cost under $50,000 each, and with more being produced, and the introduction of the "B" version, the per-shell price will fall to the planned price.

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 more than three times as much.

Developing smart artillery shells is risky. The U.S. Navy recently 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.