VANDENBERG AIR FORCE BASE, Calif., May 31 (UPI) -- More than 30 missiles on the West Coast that would defend the United States against a nuclear attack have a serious technical problem -- and nearly 20 rockets have two major flaws, an independent federal watchdog group says.
In its annual review of the U.S. missile defense system, the Government Accountability Office identified the glitches -- which could cause the interceptor missiles to fail in flight and miss hitting an enemy's incoming nuclear warheads.
All of the military's 33 Ground-Based Interceptors, which form the core of the national Ground-based Midcourse Defense (GMD) system, are affected by the glitch -- which involves problematic wiring harnesses that can interrupt the on-board guidance system that steers the rockets into enemy missiles in flight.
Investigators say unsuitable material was used to produce the wiring harnesses -- which supply power to the rocket's guidance system -- making them vulnerable to corrosion in the often damp, moldy conditions in underground silos.
Boeing, the GMD's prime contractor, informed the Pentagon of the guidance system problem last summer, but military officials believed the glitch's risk to the rockets was not great enough to warrant immediate repairs, the Los Angeles Times reported.
The GAO said the Pentagon delayed fixing the problems so it could focus on the development and deployment of new interceptors and a redesigned "kill vehicle" -- the top part of the missile that detaches from the rocket and destroys an incoming warhead.
The redesigned version would replace the first- and second-generation kill vehicles, known as Capability Enhancement I (CE-I) and Capability Enhancement II (CE-II), which are currently fitted to the entire interceptor fleet on the U.S. West Coast. The Army's Fort Greely in Alaska has 29 of the rockets, and four are located at Vandenberg Air Force Base in California. An additional eight CE-II rockets are scheduled for delivery this year. All of them are affected by the wiring glitch.
But the system's 10 CE-II interceptors already in the field, and the eight scheduled for delivery, have an additional glitch with their "divert thrusters" -- a component that helps steer the rocket in flight. This problem can also potentially cause the rocket to miss an enemy target.
The Pentagon currently has no plans to fix the defect, the GAO report said, but contractors are working to develop an alternate thruster.
According to the report, the Pentagon plans to fix the wiring harnesses in the 10 fielded CE-II vehicles this year. The remaining 23 on the CE-I rockets are scheduled for repair in 2018.
At a cost of more than $40 billion, the GMD system has seen its share of technical problems. During development of the rockets, the CE-I vehicle failed one of its three test flights -- and the CE-II failed its first two, the report said. While the third CE-II test in 2014 was a success, the GAO said the vehicle needs to achieve more successful flight testing before it can be considered reliable.
Additionally, the cost of the CE-II vehicle has gone up nearly tenfold -- from an initial cost of $236 million to an estimated $1.9 billion -- due largely to the technical difficulties that resulted from flight test failures.
"[The] plan to produce new interceptors ahead of fixing the fielded interceptors may enable the program to field additional interceptors sooner, [but] it also increases risk for the warfighter because the deployed interceptors do not have the fixes needed to address known issues," the GAO report notes.
"As such, the fielded interceptors are susceptible to experiencing the same failure modes exhibited during prior test failures, leaving the warfighter with an interceptor fleet that may not work as intended."
The Pentagon said one way to compensate for the flaws would be to simply fire more rockets at incoming enemy missiles, but the GAO countered that would be an ineffective way to defend the United States from multiple or simultaneous attacks.
The GAO also questioned why the Pentagon will pour so much money into the fixing the CE-I if it will simply replace them with a redesigned kill vehicle.
"It is unclear why MDA would expend the resources to fix the CE-Is only to begin replacing them two years later," it said.
However, the GAO report noted that expensive scenario is hardly unique given the history of the Missile Defense Agency's interceptor development over the last two decades.
"Over the past 15 years, MDA has, on average, initiated redesign or upgrade efforts for GMD approximately every two years. These efforts, while perhaps needed, have proven to be very expensive and, according to MDA, did not achieve the goal of providing the warfighter with a reliable, producible, and cost-effective interceptor," the report said.
A year ago, defense officials told Congress that the new and redesigned interceptor will undergo a more rigorous engineering and development process to try and decrease costs associated with test failures and increase reliability -- a strategy praised by the GAO report.
"The agency's recent commitment to follow a knowledge-based approach to acquire the [redesigned rocket] is a positive indication that the agency is seeking to improve its investment decisions and achieve better outcomes," it states.
In response to the report, MDA spokesman Richard Lehner said military officials have implemented "a comprehensive, disciplined program to improve and enhance" the nation's ground-based defenses concerning "the issues noted by the GAO."
"We will continue to work closely with our industry partners to ensure quality standards are not only met, but exceeded," he said.
The Pentagon aims to have 44 GMD interceptors in the field by the end of 2017, all on the West Coast. Some members of Congress have proposed positioning some of the rockets on the East Coast.
The GMD system was first put into use in 2004, in response to the Sept. 11, 2001, terrorist attacks. However, the system is effective only if the United States is faced with a "limited" attack involving a small number of missiles. It would not be effective against a massive attack involving hundreds of missiles.
The most effective deterrent against such a large-scale assault, analysts still believe, is the theory of "mutually assured destruction" -- the idea that no country would launch a nuclear first strike for fear of the catastrophic consequences of an assured counterattack.