Getting "smart shells" to work effectively is nothing new. Back in the 1980s, the 155mm Copperhead round was developed, at great expense, to take out tanks with one shot. The Copperhead was laser guided. That is, it homed in on laser light that a forward observer was creating by pointing a laser at the target. It was the same technique used with laser guided bombs. But this was expensive technology. Each of the 3,000 Copperhead shells eventually built, cost several hundred thousands dollars (the price varied, up to half a million bucks, depending on who was doing the calculating). While a "dumb" artillery shell will land with 75 meters of the aiming point, the Copperhead would land within a meter or two. But so what? It turned out there were many easier, and cheaper, ways to destroy enemy tanks. This was demonstrated during the 1991 Gulf War, when a few Copperhead shells were used, successfully, but to reactions of, "whatever."
Russia developed its own version of Copperhead, Krasnopol, and sold some to India. During a 1999 war with Pakistan, high in the Himalayan mountains, Krasnopol proved very useful in taking out enemy bunkers, without causing avalanches or destroying the few pathways up the steep hills. The Indians paid about $40,000 for each Krasnopol shell (two thirds what the Copperhead was supposed to cost originally), and found it a good investment. This encouraged the American developers of the next generation smart shell, Excalibur, which already had several years of design and research invested.
A follow on for Excalibur is a device the screws in the tip of the shell, where the fuze is usually inserted. This device, like the add-on kit the air force uses to turn dumb bombs into smart bombs, would give any shell (mainly 105mm, 155mm and 203mm) GPS guidance, at less than half the price of Excalibur.
The U.S. Army has run into more technical problems with its 155mm Excalibur "smart shell," and won't be able to deliver it until next Spring. The army has been hustling to get the Excalibur to the troops (who are eager to receive it), but testing keeps revealing more bugs in the system. This can be a problem with Excalibur, because the justification for the $50,000 shell is its ability to hit a target in situations where friendly troops are very close by. Earlier this year, there were problems with some shells not getting the GPS signal. If the Excalibur shell does not get the GPS signal, you have to make sure it's unguided trajectory will take it where there are no friendly troops or civilians. Having to do this every time you use Excalibur can be complicated, time consuming, and often not possible. These problems were solved, but then some temperature related problems were encountered. They were fixed, but still more testing must be conducted. Thus the introduction of Excalibur (in Iraq) will be delayed from this Fall to next Spring. A year ago, Excalibur was scheduled for delivery to the troops right about now.