Defense officials will conduct another test of a controversial proposed U.S. anti missile system on Saturday.
This will be the fifth test in which a so-called "kill vehicle" will attempt to intercept and destroy a warhead launched aboard a long range ballistic missile.
Air Force Lieutenant General Ronald Kadish, head of the U.S. Ballistic Missile Defense Organization, notes two of the previous tests have failed while two have resulted in successful intercepts.
Still, he said, whether the new test results in a successful intercept or not, researchers will learn from it."We are testing to learn. We are not testing as pass-fail for some operational reason...we're learning about the system. We'll make corrections as a result of any anomalies and we'll continue to test to build our confidence and to learn more until such time as we feel confident to do operational testing against more realistic targets and more realistic scenarios," he said.
The test will involve the launch of a three-stage Minuteman missile from California, which will deploy a dummy warhead and a single balloon-shaped decoy.
About 20 minutes after the missile launch, a second missile carrying the interceptor will be sent aloft from Kwajalein Atoll in the Pacific. An estimated 10 minutes later, the Pentagon said the intercept should take place at an altitude of about 225 kilometers over the central Pacific.
The systems being tested include not only the interceptor but also a space based missile warning sensor, ground based early warning radars and a complex battle management command, control and communications system.
The Bush Administration has been pushing for development of an anti missile system to provide the United States a defense against possible ballistic missile attack by a rogue state such as North Korea or Iraq.
But the program has drawn fire from several countries, including some NATO allies, China and Russia.
General Kadish said the test will not violate the Anti Ballistic Missile Treaty signed by the United States and the former Soviet Union in 1972. The Bush Administration said that treaty, adopted during the Cold War, is outdated.