A ground-based ballistic missile interceptor was launched from Vandenberg Air Force Base, Calif. in a non-intercept flight test in January. A similar missile failed to intercept its target as planned in a July 5 test.

It will be some time before the Pentagon pinpoints the cause of a recent failed intercept test of the nation's system of ground-based missile interceptors, which features a kinetic warhead made by Tucson-based Raytheon Missile Systems.

But one thing is clear: The test failure has cast a new pall over the program, just as the Pentagon wants to boost confidence that the U.S. can repel a North Korean ballistic missile strike.

And while giving new ammo to missile-defense critics who say the multi-billion-dollar program is a deeply flawed waste of money, the test failure also elicited calls to spend more money to fix the problems.

In the July 5 test, an interceptor of the Ground-based Midcourse Defense system launched from Vandenberg Air Force Base in California failed to intercept a long-range ballistic missile target launched from the U.S. Army's Reagan Test Site on Kwajalein Atoll, Republic of the Marshall Islands.

Though announcements of successful tests often include details of each mission step, the Missile Defense Agency offered only that during the most recent test "an intercept was not achieved."

"Program officials will conduct an extensive review to determine the cause or causes of any anomalies which may have prevented a successful intercept," the agency said.

The test missile featured an older version of the Exoatmospheric Kill Vehicle, a nonexplosive "hit-to-kill" warhead made by Raytheon in Tucson and the same version that is on 20 of the 30 ground-based interceptors currently deployed in California and Alaska. A newer version of the warhead failed its last test in 2010 and was scheduled to be tested later this year.

Raytheon referred questions about the failed test to the program's prime contractor, Boeing Co., and the Missile Defense Agency. In addition to the EKV, Raytheon makes the Standard Missile-3 interceptor for the sea-based Aegis Ballistic Missile Defense system.

In a prepared statement, Boeing said it will work with the MDA to analyze the failure - the third failed test in a row, counting two misses in 2010.

"Boeing is proud to support the only defense the United States has against long-range ballistic missiles. GMD has a proven track record of success and Boeing is committed to maintaining this capability in the face of evolving threats," the company said in an email from spokeswoman Jessica Carlton.

It typically takes weeks or months for the Pentagon to complete test failure reviews.

But a major missile-defense advocate said that preliminary findings indicate that the final stage failed to separate from the rocket, rather than a failure of Raytheon's kill vehicle to detect or track the target.

Riki Ellison, chairman and founder of the Virginia-based Missile Defense Advocacy Alliance, wrote last week that initial indications are that other fundamental parts of the system, including multi-sensor land, sea and space tracking, communications and initial targeting worked correctly.

Ellison, a frequent visitor to missile-defense sites who has witnessed 25 missile-defense tests, named no other source for the preliminary findings.

He said the root cause must be found and investigators must determine if the problem was an anomaly with the one missile or a systematic problem with all of the deployed interceptors, urging a quick retest and more frequent testing overall.

"For our national security, in today's world, we cannot as a nation afford to go without annual testing of this system," said Ellison, an Amphitheater High School graduate and former pro football player.

The test failure renewed calls by critics to halt the program, at least until flaws can be fixed.

Philip Coyle, a former senior Pentagon weapons testing manager and current senior science fellow at the Center for Arms Control and Non-Proliferation, called the test "another big setback for the MDA," citing the program's record of three successful intercepts in 10 tries since 2002.

"Whether you count the performance over the past five years or the last 10, clearly the GMD system is something the U.S. military, and the American people, cannot depend upon," said Coyle, who headed the Pentagon's operational test and evaluation arm for six years and was a White House technology and security adviser from 2010 to 2011.

Coyle said the plan by Defense Secretary Chuck Hagel to deploy 14 more interceptors at the ground-based missile defense site at Fort Greely, Alaska - or at a proposed new East Coast site - "would be throwing good money after bad."

The Pentagon said it remains confident in the system.

"We believe that we have a robust missile defense architecture in place and we are in a position to respond to any threat that emanates from North Korea," Pentagon spokesman George Little said. "Our faith in our missile defense programs remains strong and every healthy organization takes stock of mishaps when they occur, and that's what we're doing now."

But Coyle noted that the failed test involved the older version of the Exoatmospheric Kill Vehicle, known as the CE-I, which he said has performed poorly in the past.

And Coyle said the Pentagon's decision to move forward with the additional interceptors in Alaska is precariously tied to the results of a single, future intercept test of the newer, "but still unproven" CE-II version of the kill vehicle, scheduled for later this year.

He noted that the National Research Council has recommended that the Missile Defense Agency develop a faster, new booster and a more capable kill vehicle to replace the EKV altogether.

Congress has taken notice of the program's problems as well.

On Friday, four Republican members of Congress blamed the Obama administration for cutting funding to upgrade and adequately test the ground-based Interceptor and its troublesome kill vehicles.

The members, including House Armed Services Committee Chairman Howard P. "Buck" McKeon, R-Calif., called on Defense Secretary Hagel to retest the ground-based Interceptor as soon as possible and to make development of an entirely new, next-generation kill vehicle a top priority.

test record

The Ground-based Midcourse Defense system, which consists of 30 missile interceptors in California and Alaska, has had a spotty flight-test history, succeeding in eight of 16 attempts since 1999 (three successful intercepts using operationally configured interceptors), according to the Missile Defense Agency.

Here's a look at the test failures by date, with causes:

• Jan. 2000 - Kill vehicle's infrared sensor cooling malfunctioned.

• July 2000 - Kill vehicle and booster did not separate.

• Dec. 2002 - Kill vehicle and booster did not separate.

• Dec. 2004 - Interceptor failed to launch due to problematic software configuration.

• Feb. 2005 - Interceptor failed to launch after a silo support arm did not retract, triggering an automatic abort.

• May 2002 - Target malfunction (interceptor not launched).

• Jan. 2010 - Kill vehicle and system sensor performance issues.

• Dec. 2010 - Kill vehicle guidance error in final seconds of flight.

• July 5, 2013 - Pending failure review.

Source: U.S. Missile Defense Agency

Contact Assistant Business Editor David Wichner at dwichner@azstarnet.com or 573-4181.