Seeker fault cited in failure of missile defense intercept testAerospace Daily January 20, 2000
Pentagon officials said a national missile defense (NMD) kill vehicle failed to hit a target warhead in a test Tuesday because of a problem with its infrared seekers just seconds before the intercept was to have taken place.
There are two IR seekers on the Raytheon-built exoatmospheric kill vehicle (EKV) and preliminary analysis shows that at least one of them did not work, a senior military official said.
In the test, a modified Minuteman ICBM with the target vehicle aboard was launched from Vandenberg AFB, Calif., at 6:19 p.m. PST. The EKV was launched about 20 minutes from Kwajalein Atoll in the Pacific, about 4,300 miles away. The EKV was expected to intercept the target somewhere over the ocean.
An EKV used in the first NMD intercept test in October hit the target within 10% of its "sweet spot" - the area where program experts wanted it to hit. Officials acknowledged last week that there were some glitches in that test but stressed that a hit is a hit (DAILY, Jan. 18).
The IR sensor mishap occurred about six seconds before the intercept, the official said.
All the tracking data leading up to a hit from Defense Support Program satellites and the Ground Based Radar Prototype (GBR-P) came through as planned, or better than expected. For example, the GBR-P began tracking the target earlier than anticipated, the official noted.
The data shows that after separation from the payload launch vehicle, the EKV correctly conducted two star-shots to determine its location as compared with that of the target. Problems encountered in an October test with the star-shot were not an issue in Tuesday's test.
The EKV then identified the target complex, which includes a decoy, and moved toward a kill. However, the IR seeker is needed for the final homing in maneuver and that did not work. Another visual light seeker on the EKV does not perform that final step, the official explained.
The Pentagon expects to analyze data for weeks to come, but has made no change in plans to test again in the late April/early May timeframe, the official said. Tuesday's test cost $ 100 million.
Senior Dept. of Defense officials, briefing reporters, said flight test misses wouldn't necessarily mean they would recommend against deployment. They also said that if intercepts were achieved in all the tests, they wouldn't guarantee a green light for deployment.
Under the current plan, three tests are to be conducted before a June deployment readiness review, in which DOD will present a recommendation to the president on whether an initial site should be activated by 2005. President Clinton will make the final call.
A special panel, headed by retired Air Force Gen. Larry Welch, in November reported numerous schedule and technical problems in the NMD program and recommended the deployment decision be adjusted if there were slips or further problems (DAILY, Nov. 12, 13). Topping the Welch list of "high risk" items is the EKV. While it had been performing well prior to the report's release, the panel cautioned that the difficulty of the hit-to-kill technique was underestimated.
Yesterday, NMD program supporters were quick to remind their opponents that the reason to test a system in the first place was to discover glitches and improve performance.
"If we stopped every testing program after one failure, the Wright Brothers would never have gotten off the ground at Kitty Hawk, the United States never would have launched a man into space, and our nation never would have sent a man to walk on the moon," said Rep. Curt Weldon (R-Pa.), a top supporter of NMD. "You take a test, learn from your mistakes and improve upon the efficiency and capabilities of the technology."
Weldon declined to speculate on what effect the test would have on the president's plan to make a deployment decision in June.
"In the view of the Congress, a deployment decision has already been made," Weldon said. "Legislation passed overwhelmingly by Congress last year and signed into law by President Clinton make it the official policy of the United States to deploy a national missile defense. The president's plan to make a decision in June is nothing more than political posturing in a presidential election year."
Sen. James M. Inhofe (R-Okla.) said the "failure will not deter America's determination to develop and deploy an effective national missile defense system....This is not an easy task, but it is one that is both technologically achievable and morally right. As we pursue this mission in the months and years ahead, there will be both successes and setbacks. We must learn from both and apply that knowledge to perfecting our systems and methods...."
The Clinton Administration has been reluctant to support early deployment, while the GOP-led Congress has pushed for development and deployment as soon as possible. Some observers think Clinton may give a green light to deploy simply to defuse the NMD issue as a campaign problem for Vice President Al Gore. GOP presidential contender George W. Bush already has come out strongly in support of an NMD deployment.
"The deployment decision has a lot more to do with defending Al Gore from George W. Bush than from defending America from missiles," said John Pike of the Federation of American Scientists.
The best way for Clinton to make NMD a non-issue for Gore is to give an okay for deployment, which would be easier if there were three successful intercept tests before the review, Pike added. The next test is slated for late April.
Boeing is the lead system integrator for the NMD program. Lockheed Martin builds the launch vehicle that carries the EKV.
Copyright 2000 The McGraw-Hill Companies, Inc.