Romania has agreed to base American anti-missile systems on its territory. These will probably be land based Aegis systems. So far, Aegis has achieved an 83 percent success rate during live test firings. So now everyone wants an Aegis ABM (Anti-Ballistic Missile) ship for protection. The Aegis system was designed to operate aboard warships (cruisers and destroyers that have been equipped with the special software that enables the AEGIS radar system to detect and track incoming ballistic missiles). However, there is also a land based version that Israel is interested in buying. The development version of AEGIS was land based, and is still in operation. The U.S. wants to put anti-missile systems in Eastern Europe to protect against ballistic missile attacks from Iran. Russia sees this as a subterfuge to weaken the effect of Russian ballistic missiles.
Currently, the navy has 20 ships with the Aegis anti-missile system (soon to be 27). There are over 100 American and foreign warships equipped with Aegis. Converting an Aegis ship to Aegis ABM costs about $12 million, mainly for new software and a few new hardware items. This is seen as a safe investment. To knock down ballistic missiles, Aegis uses two similar models of the U.S. Navy Standard anti-aircraft missile, in addition to a modified version of the Aegis radar system, which can now track incoming ballistic missiles.
The anti-missile missile is the RIM-161A, also known as the Standard Missile 3 (or SM-3). It has a range of over 500 kilometers and max altitude of over 160 kilometers. The Standard 3 is based on the anti-missile version of the Standard 2 (SM-2 Block IV). This SM-2 missile turned out to be effective against ballistic missile warheads that are closer to their target. One test saw a SM-2 Block IV missile destroy a warhead that was only 19 kilometers up. An SM-3 missile can destroy a warhead that is more than 200 kilometers up. But the SM-3 is only good for anti-missile work, while the SM-2 Block IV can be used against both ballistic missiles and aircraft. The SM-2 Block IV also costs less than half what an SM-3 costs.
The SM-3 has four stages. The first two boost the interceptor out of the atmosphere. The third stage fires twice to boost the interceptor farther beyond the earth's atmosphere. Prior to each motor firing it takes a GPS reading to correct course for approaching the target. The fourth stage is the 20 pound LEAP kill vehicle, which uses infrared sensors to close on the target and ram it.
The U.S. wanted to put silos for the GBI (Ground Based Interceptors) in Romania, but Russia is very much against this, as they see it as diluting the intimidation effect of their ICBM force. The GBI is a 12.7 ton ballistic missile that delivers a 140 pound "kill vehicle" that will intercept a ballistic missile before it begins its descent into the atmosphere. The GBI kill vehicle attempts to destroy the incoming missile, while avoiding decoys.
The U.S. already has GBIs deployed in Alaska and three in California. The GBI can receive target information from a variety of source, mainly a large X-band radar and space based sensors (that can detect ballistic missiles during their initial launch.) The Czech Republic has agreed to allow an X-band radar to be set up on its territory. The U.S. plans to install 5-10 GBIs a year over the next few years. Each GBI costs over $100 million (up to several hundred million dollars, depending on how many are built and how you allocated development costs.) The GBI can intercept ballistic missiles launched from as far away as 5,000 kilometers.