The U.S. Army's new Excalibur "smart shell" is going to Iraq this Fall. Each shell will cost about $80,000. Half of that is actual manufacturing cost, the other half is fifteen years worth of development expenses. One reason development took so long, and cost so much (over a billion dollars) was that, initially, Excalibur was going to be less accurate, and just disperse a few bomblets that would cripple tanks and kill infantry. But in 1998, it was found possible to include much more accurate GPS guidance. Three years later, it was decided to dispense with the bomblets and just use a high explosive shell. After 2001, it became obvious the highly accurate weapons were all the troops wanted. GPS guided JDAM smart bombs showed that. So Excalibur had to adapt, and is now basically an artillery version of JDAM.
But JDAM is a formidable competitor. The hundred pound, 155mm shell has to compete with the new U.S. Air Force "small diameter bomb" (SDB). This 250 pound device, which looks like a missile, but is an unguided smart bomb, weighs twice as much as Excalibur, and thus produces a bigger bang. But you need an air force bomber overhead to get a SDB, while army artillery is always there. You also need an air force FAC (Forward Air Controller) nearby to call in the bomb, while there are many more army personnel who can call for artillery. The SDB costs about 30 percent more than Excalibur. Another competitor is the GPS guided MLRS rocket. But because rockets are less accurate than artillery shells to begin with, GPS guided MLRS cannot hit targets as accurately as SDB or Excalibur, and is already in Iraq.
An even cheaper smart shell is also in development. This is the Projectile Guidance Kit (PGK), which is actually a large fuze, that screws into the front of a 155mm or 105mm shell. This longer fuze contains a GPS and small fins to guide the shell to a precision hit equal to an Excalibur shell. The army doesn't expect to be passing these out to the troops for another five years. But if development goes smoothly, and Excalibur proves useful and popular, then the PGK might show up earlier. The PGK will cost less than half what each Excalibur does and, more importantly, can turn any shell into a smart shell. This is important for artillerymen, who don't like to carry around a lot of special shells, just in case. Artillery units already carry several different types of fuzes for their shells, so one more is not seen as a burden.
The pinnacle of artillery operations has always been, "one shot, one kill." But achieving this has always been like a golfer getting a hole in one. It can be done, but it's rare. Smart shells make "one shot, one kill" commonplace, and means artillerymen will spend less time constantly replenishing their ammunition supplies. Firing the cannon less often is also nice, as those beasts are a bitch to keep clean.