July 8 (Reuters) - The United States and the Czech Republic will sign a pact on Tuesday for the central European country to host a radar system, part of U.S. plans to create a missile defence shield in Europe.
The proposed shield, which also envisions up to 10 interceptor missiles in Poland, is meant to defend against what Washington says is the potential threat of a missile attack from Iran against European and U.S. targets.
The project needs approval in Poland and faces a tough parliamentary ratification process in the Czech Republic, where more than two thirds of the public oppose the plan. Russia is opposed to it and says it will threaten its security.
Following are some details about the proposed missile shield.
THE PERCEIVED THREAT
* General Henry Obering, head of the Pentagon's Missile Defence Agency (MDA), has said U.S. intelligence suggests that by 2015, Iran could follow North Korea's example and develop a long-range missile capable of striking the United Sates.
* The United States brought an earlier anti-missile umbrella, based in Alaska and California, on line in 2004 to protect against the perceived North Korean threat. The Czech and Polish sites would augment that system.
* Washington has tried to quell concerns in Moscow that the system would pose a threat to Russia by highlighting that the shield's missiles are defensive only -- carrying no warheads -- and would be no match for Russia's nuclear arsenal.
THE TECHNOLOGY
* The proposed $3.5 billion system would use "hit-to-kill" technology in which an array of sensors and radar would detect an enemy missile in flight and guide a ground-based interceptor to destroy it.
* Without using explosives, the interceptor would ram an incoming warhead at a closing speed of 15,000 miles per hour (24,000 kph) in a process likened to hitting a bullet with another bullet in space.
* The MDA says tests show the technology is sound. But critics, including the Washington-based Centre for Defense Information, say the evidence is misleading, many tests were made in controlled circumstances not resembling real attacks, and more results are needed to prove the system works.
THE PLAN
* The radar installation planned for the Czech Republic would aim its coverage towards the Middle East to detect a missile in flight and guide interceptor missiles into the trajectory of the approaching warhead.
* Washington has proposed placing as many as 10 interceptor missiles with a range of up to 1,800 miles (3,000 km) in Poland, The missiles would be housed in underground silos in an area about the size of a football field.
* Poland and the United States have reached a tentative deal on installing the U.S. anti-missile base there, but Warsaw has yet to fully agree and wants billions of dollars from the United States to upgrade its air defence systems.
* If approved, construction on both sites could begin in 2009, and could begin functioning in 2011-2013. (Sources: U.S. Missile Defense Agency, Pentagon, Centre for Defense Information) (Compiled by Michael Winfrey; Editing by Charles Dick)