WASHINGTON (AP) -- Major delays, cost overruns and critical technological problems are plaguing a missile defense system designed to protect the United States and Europe from an Iranian attack, Pentagon advisers and government investigators say about one of President Barack Obama's top military programs.
The reports cast doubt on the shield, a politically sensitive issue at home and in relations with Russia. They say missile interceptors are running into production glitches, radars are underpowered and sensors cannot distinguish between warheads and other objects.
A report by the Defense Science Board, an advisory group to the Defense Department, came out late last year but received little notice. While it concludes there are "no fundamental roadblocks" to the system, it points out big problems without saying how they can be fixed.
Board members declined repeated requests for comment. Outside experts, including the Pentagon's former chief weapons tester, Philip Coyle, say the issues raised in the report would require substantial and costly changes, if they can all be surmounted at all.
The second report, by Congress' nonpartisan Government Accountability Office, was released Friday.
Some Republicans say the reports support their view that the program was designed hastily to ease the concerns of Russia, which had objected to previous missile defense plans by the Bush administration, with less regard to whether it would work. Ahead of this November's election, Republicans are casting Obama as a weak leader, quick to capitulate to the demands of other nations.
"There is a political timeline and agenda that doesn't meet a scientific, development and security timeline," said Rep. Michael Turner, chairman of a House panel that oversees missile defense. "It does not appear that it can deliver the protection for U.S. homeland that this administration promised," said Turner, R-Ohio.
The administration insists the plans are on track.
Missile defense in Europe has been a nettlesome issue since the middle of last decade, when President George W. Bush announced plans to base long-range interceptors in central Europe as a defense against missiles from Iran. That infuriated Russia, which believed the program was intended to counter Moscow's intercontinental ballistic missiles and undermine its nuclear deterrent. Some Democrats also objected, complaining the U.S. was gambling billions of dollars on questionable technology.
Soon after Obama took office in 2009, he revamped the program as he looked to improve relations with Moscow. His plans called for slower interceptors that could address Iran's medium-range missiles. The interceptors would be upgraded gradually over four phases, culminating in 2020 with newer versions, still in development, that the administration says will protect Europe and the United States. The early phases call for using Aegis radars on ships and a more powerful radar based in Turkey. Later phases call for moving Aegis radars to Romania and Poland.
The plans have gained momentum in Europe with the signing of basing agreements in Poland, Romania and Turkey, as well as backing by NATO.
Obama claims his system would be more reliable than what had been planned by Bush because the new plan was based on tested technology.
"We have made specific and proven advances in our missile defense technology," Obama said at the time. "Our new approach will, therefore, deploy technologies that are proven and cost-effective and that counter the current threat, and do so sooner than the previous program."
But the two reports cast doubt on the technology and Obama's timetable.
The advisory board found that the ship-based Aegis radars would have too short a range to provide enough time for the ship's interceptors to hit the target, a capability it says is essential for coverage for Europe. .
This report also said the range of the Turkey-based radar would need to be substantially longer to detect and track attacking missiles early enough to protect Europe. It said that it was not clear how to do the upgrades.
Rick Lehner, a spokesman for the U.S. Missile Defense Agency, rejected the findings, saying the radars will be powerful enough to detect missiles. In a statement, he also said the U.S. also plans to augment the tracking ability with a constellation of satellites within nine years.
The board's report also said engineers have not been able to demonstrate that the system's sensors can tell whether an interceptor has destroyed a warhead because the sensors cannot distinguish between a warhead and other objects, such as a piece of a destroyed rocket.
That concern, which also applies to other U.S. missile defense systems, would back up the findings of a longtime critic of missile defense, MIT scientist Ted Postol. He has argued that adversaries could overcome the U.S. shield by using decoy warheads, such as balloons, when they launch a missile.
"If you can't tell the difference between a warhead and pieces of debris from an attempted intercept, how are you going to identify a decoy that's designed to fool you?" Postol said.
The board's report said that if the system is firing its limited number of interceptors at junk or decoys, the result would be "dramatic and devastating."
Lehner acknowledged that identifying warheads remains difficult but said the current technology is adequate to counter the threat from "rogue nations" and is continuing to improve.
Coyle, who oversaw weapons testing in 1990s and recently was a science adviser to Obama, said it is not clear how or whether engineers can address the problem of decoys.
"Clearly, from their report, the DSB believes that these systems require major changes," he said.
A renowned physicist who has read the report, Richard Garwin, said the problems identified in the report appear too overwhelming to overcome.
"If you would only replace the radars by real radars and you replace the interceptors by faster interceptors and you find some way of discriminating between a warhead and a decoy, then yes, it's a good foundation for moving forward," he said sarcastically.
Congressional investigators said the Defense Department is committing to technologies before they are proven and that the administration is risking "performance shortfalls, unexpected cost increases, schedule delays and test problems."
Key parts of the system are already experiencing problems. For instance, the GAO report said pressure to meet Obama's 2015 deadline to field the second phase of the system has led the Defense Department to order dozens of interceptors even though it's not clear they will work. Testing isn't expected to be completed until next year.
The report raised larger concerns for the interceptors planned for the last two stages.
On the third-stage interceptor, the report says critical technologies in its rocket motors had problems during testing that may require redesign. The report also criticizes the administration for setting out a timeline that calls for scheduling a test for the final interceptor a year before the military can confirm whether its design can work.
Similarly, the report says the military plans to install its radar in Romania before it is tested, and that the radar could interfere with Romanian cellphone, data, television and radio broadcasts unless it is altered.
Lehner, the Missile Defense Agency spokesman, said that claim is being examined. If there is a problem, the U.S. would work to resolve it, he said. "This is something we take very seriously."
Missile Defense Agency: http://www.mda.mil/system/system.html
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