The concept is attractive and the U.S. and Israel are the latest nations to try and make it work. There have been problems. Three years ago the U.S. Army cancelled its NetFires (or NLOS-LS) missile system, which is very similar to Hoplite. With the successful introduction of GPS guided rockets, artillery, and mortar shells, NetFires was redundant, too expensive, and still in development. The army has already spent $1.21 billion on NetFires development and was due to spend another $431 million. The navy briefly sought to adapt NetFires for use on ships, but that did not work out either.
When development of NetFires began in 2004, the project was only supposed to cost $1.1 billion and be completed within six years. But there were problems and more money and time was needed. Each missile was supposed to eventually cost at least $50,000 (if the original plan to buy nearly 10,000 missiles was implemented). However, the first missiles would cost about ten times that. Early on the navy let it be known that it would buy NetFires to arm its new LCS (Littoral Combat Ships). The navy apparently did not want to look for a replacement weapon and was confident enough in NetFires to try and take it over when the army quit. There were few good alternatives here, as the LCS isn't really big enough to handle the standard navy VLS (Vertical Launch System), which handles much larger anti-aircraft, anti-ship and cruise missiles in other ships. The LCS is still looking for a suitable missile system.
NetFires was actually two different missiles, identical in weight and size but different in how they operated. The main one was PAM (Precision Attack Missile). This was a 178mm diameter missile that weighs 55 kg (120 pounds) and had a range of 40 kilometers. PAM attacked from above, with a 13.2 kg (28 pound) warhead. This enabled it to kill any tank by hitting the thinner top armor. PAMs were vertically-launched from what looks like a 1.3x1.9x1.3 meter (4x6x4 foot wide x deep x high) cargo container. Actually, it was a cargo container. The missiles were shipped from the factory in this sealed container. Each one ton container held 15 missiles and could be carried on the back of a truck or a ship. Once you plugged a PAM container into the wireless battlefield Internet, the missiles were ready to fire. The fire control officer on the ground or an LCS sent one or more PAMs against any enemy target that showed up on their screen (usually a larger flat screen). The battlefield Internet used aircraft, UAVs, satellites, and ground sensors to pick up targets. When the fire control officer saw a target needing to be hit, a point and click sent the coordinates of the target to a PAM container, launched a PAM to the approximate location where the missiles own sensor picked up the target and homed in on it. The sensors would, most of the time, identify vehicles already destroyed and adjust the fire control officer’s screen accordingly.
Recognizing that there would be situations, like where there are a lot of woods or jungles that would prevent sensors from spotting a lot of targets, there was a second NetFires missile, the LAM (Loitering Attack Missile). Same weight and all of the PAM, except it is actually a mini-cruise missile and could fly around an assigned area for 45 minutes looking for a target. If one was not found, it just crashed. If a target was detected with the built in radar (laser radar, or LADAR, actually) and the built in software recognized the vehicle as an enemy one, the missile attacked from above. Alas, the LAM warhead wasn't large enough to take out most tanks, but anything else would likely be toast. The navy sought to use LAM against missile and torpedo boats, as the LAM could search about 150 kilometers from the ship for targets.
Meanwhile, Israel developed something similar to PAM. This was simply a new version of the Israeli Spike missile, one with a range of 25 kilometers. This version weighed 70kg (155 pounds), twice what the current largest version of Spike weighs. Spike is a series of anti-tank (or whatever) missiles with ranges from 200-8,000 meters. The 25 kilometers version is called Spike NLOS (Non Line-Of-Sight), meaning that it can be fired at a target the operator cannot see (but someone else, with a laser designator, can see). There was not a lot of demand for Spike NLOS, but at least the Israelis got it into service.