A ballistic-missile interceptor made by Tucson-based Raytheon Missile Systems has been ruled out as the cause of a failed intercept test in late June, the U.S. Missile Defense Agency says.

The agency also eliminated the Aegis Weapon System, made by Lockheed Martin, as the cause of the failure of a June 22 flight test off Hawaii, in which a Raytheon Standard Missile-3 Block IIA interceptor failed to intercept a medium-range ballistic missile target.

In a statement initially made to Aviation Week, agency Director Lt. Gen. Sam Greaves said the interceptor and the Aegis combat weapon control system were not to blame based on the agency’s initial investigation, but he declined further comment.

“Though the review is still in process, the SM-3 IIA interceptor and Aegis Combat System have been eliminated as the potential root cause,” Greaves said. “We are conducting an extensive review as part of our standard engineering and test processes, and it would be inappropriate to comment further until we complete the investigation.”

The SM-3 Block IIA, which is under joint development with Japan, is a bigger and faster version of the SM-3 missile interceptors currently deployed on U.S. and Japanese ships.

During the June 22 test, a medium-range ballistic target missile was launched from the Pacific Missile Range Facility at Kauai, Hawaii.

The guided missile destroyer USS John Paul Jones detected and tracked the target missile with its onboard radar and launched one SM-3 Block IIA missile, but the missile did not intercept the target, the MDA said.

The failed test followed a successful intercept of another medium-range target by the same type of missile in February.

The agency is not commenting on the impact the test failure will have on the SM-3 Block IIA development program or the prospect of a retest, spokesman Christopher Johnson said.

The SM-3 Block IIA had been on track for deployment by the end of 2018, with additional intercept tests planned.

A missile-defense advocate said the agency now likely will be looking at “human error” as cause for the test failure.

“That’s a procedural issue, and it’s an easy fix,” said Riki Ellison, founder and chairman of the nonprofit Missile Defense Advocacy Alliance, adding that he doesn’t think the issue will hold up the SM-3 Block IIA development schedule.

Contact senior reporter David Wichner at dwichner@tucson.com or 573-4181. On Twitter: @dwichner

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