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– Frank von Hippel
Co-Director of Program on Science and Global Security, Princeton University
June 1, 2018
Sea-Based Missile Defense System Misses Target

Wade Boese

A sea-based theater missile defense system scheduled for deployment within the next two years suffered its first failure in four intercept tries June 18. The Pentagon is now trying to figure out what went wrong.

In its first test since November 2002, the Aegis Ballistic Missile Defense system was supposed to destroy a target missile minutes after its launch from Kauai Island, Hawaii. If all had worked according to plan, a kill vehicle on a Standard Missile-3 (SM-3) interceptor fired from the USS Lake Erie was to home in and collide with an Aries ballistic missile target as it rose into space. Instead, the kill vehicle and the Aries target flew past each other.

A day after the miss, Rick Lehner, a spokesman for the Pentagon’s Missile Defense Agency (MDA), explained that everything seemed to be going correctly seconds before the expected impact, but then the kill vehicle lost the target in the “end game.” How much distance separated the two is uncertain, though Lehner said that it “appeared to be close.”

The kill vehicle was an updated version of ones employed in previous tests. In a June 16 statement, the Pentagon said the new design was intended to “improve performance and improved production.”

Another twist differentiating the June test from its predecessors was the inclusion of a second ship, which tracked the target first and then relayed intercept data to the USS Lake Erie. Lehner said this aspect of the test “worked fine.”

The latest test marked the second in a series of six tests to be completed by the end of 2005. Unless MDA repeats the June scenario, the next test will feature a target with a separating warhead. In the tests to date, the Aries missile stays in one piece, making it a bigger target.

Up to 20 SM-3 interceptors, designed to counter short- and medium-range ballistic missiles, are to be deployed on three Aegis ships as part of the Bush administration’s limited missile defense deployment scheduled for 2004 and 2005. The Pentagon also plans to outfit another 15 ships with upgraded radars to track ballistic missiles.

The Aegis Ballistic Missile Defense system—formerly known as the sea-based midcourse defense and, before that, Navy Theater Wide—is not the only missile defense system set for near-term deployment that has suffered a letdown in its most recent test. The ground-based interceptor system designed to defend against long-range ballistic missiles also failed in a December 2002 intercept test.