WASHINGTON — The director of the U.S. Missile Defense Agency told lawmakers March 25 that the results of a planned intercept test of the troubled U.S. national missile shield this summer would not influence his decision to pursue a new kill vehicle for the system.

Testifying before the House Armed Services strategic forces subcommittee, Navy Vice Adm. James Syring said the agency plans to test, as expected, the Capability Enhancement 2 exo-atmospheric kill vehicle (EKV) this summer. Capability Enhancement 2 is the upgraded version of the EKV, which is designed to separate from its booster rocket and destroy missile warheads by force of impact.

The test will help determine whether the technology on the Capability Enhancement 2 kill vehicle has advanced enough for the Pentagon to buy 14 more Ground-based Midcourse Defense (GMD) interceptors for installation at Fort Greely, Alaska. The planned purchase is a key part of the Obama administration’s plan to bolster the nation’s defenses against an attack from North Korea.

But Syring stressed that whatever happens in the test, the agency will go forward with development of a new EKV, the impetus for which was a number of problems with the current EKV that cropped up during testing. The MDA’s 2015 budget request includes nearly $100 million to redesign the kill vehicle that tops the GMD interceptors.

While acknowledging that “testing is the ultimate graduation exercise” in the missile defense world, Syring said “the success or failure of the test this summer will in no way change my mind about a new EKV.”

Concerns about the EKV’s reliability stem from three consecutive GMD intercept failures. At least two of those failures, the latest of which occurred in July, have been attributed to issues with the EKV.

Syring said the July test did not lead to an intercept because “the kill vehicle on the [interceptor] did not separate from the booster’s third stage.”

Experts had long suspected the kill vehicle, produced by Raytheon Missile Systems of Tucson, Ariz., failed to separate from its booster rocket, supplied by Orbital Sciences Corp. of Dulles, Va. Boeing Defense, Space & Security of St. Louis is overall prime contractor on the GMD.

“Once the investigation is concluded, we will take steps to make any fixes to the fleet that need to be made for both” of the current EKV variants, Syring said.

All told, the GMD system has recorded eight intercepts in 16 flight tests since 1999.

In written testimony, Syring said a nonintercept flight test in January 2013 proved the agency had corrected a navigation system issue identified as the cause of a failed intercept in December 2010.

Syring also said work continues on a potential third interceptor site in the United States.

The current U.S. territorial shield features interceptors at two sites: four at Vandenberg Air Force Base, Calif., and 26 at Fort Greely. U.S. Defense Secretary Chuck Hagel announced in March 2013 that the MDA would increase the number of interceptors at Fort Greely and scout sites for a third U.S. installation, something Republican lawmakers have been pushing for longer than a year.

Lt. Gen. David Mann, commander of U.S. Army Space and Missile Defense Command in Huntsville, Ala., told the panel a third site would disperse the arsenal and allow decision makers more time to characterize incoming threats.

The Pentagon recently announced it would conduct environmental impact studies at four sites. Syring said those studies will take approximately 24 months, which he described as an “aggressive” pace.

“All of that work is setting the stage for a decision,” Syring said.

The site would cost more than $3 billion, including the price of 20 interceptors, Syring said.

“While there has been no decision by the Department to move forward with an additional [contiguous United States] interceptor site, such a site would add battle space and interceptor capacity should it be deemed necessary to proceed with deployment,” Syring said in written testimony.

Mike Gruss covers military space issues, including the U.S. Air Force and Missile Defense Agency, for SpaceNews. He is a graduate of Miami University in Oxford, Ohio.