Missile silo at Fort Greely

Navy Capt. Frank Bradley, executive assistant to Gen. Joseph F. Dunford Jr., chairman of the Joint Chiefs of Staff, tours the 49th Missile Defense Battalion at Fort Greeley, Alaska, Aug. 19, 2017. The soldiers guard the ground-based interceptor missiles at the base. (DOD photo by U.S. Navy Petty Officer 1st Class Dominique A. Pineiro)

Members of Alaska's congressional delegation say they are worried about the recent Pentagon decision to terminate a billion-dollar contract with Boeing to develop and update weapons designed to divert and destroy incoming missiles.

The Pentagon on Wednesday announced the decision, which went into effect Thursday, citing design problems with the Redesigned Kill Vehicle component that "were so significant as to be either insurmountable or too costly to correct," according to information provided to The Associated Press.

The Pentagon has 44 missile interceptors based mostly in Alaska — at Fort Greely near Delta Junction — that are designed to be launched from an underground silo, travel outside the Earth's atmosphere and release a "kill vehicle" — a device that steers into its target and destroys it by force of collision.

These weapons have been tested but never used in actual combat.

It is that "kill vehicle" device that the Pentagon had asked Boeing to redesign so that it could be more reliable against the kind of long-range missiles that North Korea has said it is building to target the U.S.

Alaska Republican Sen. Lisa Murkowski called the cancellation of the contract "disappointing" but noted she understood the need for updates.

“In the face of continually evolving threats, it makes sense for the U.S. military to also make sure our defense systems are evolving," she said in a statement sent to the Daily News-Miner. "While it is disappointing the Pentagon canceled the contract prior to placing an additional 20 ground-based interceptors in our state, Alaska remains a strategic location."

The senator said it's likely that missile defense work in Alaska will continue even with the change in defense equipment development.

"It is my understanding that construction of Missile Field 4 at Fort Greely will continue, and once the next-generation interceptors are built," Murkowski added. "I will work to ensure that those will be placed in Alaska to serve as our nation’s first line of defense.”

Murkowski does not serve on any Senate committees directly connected to defense but does hold a position on the Senate Appropriations Committee, which is often involved in defense funding conversations.

Alaska Republican Sen. Dan Sullivan serves on the Senate Committee on Armed Services and said he was troubled by the change.

"Given the continued evolution of advanced adversaries’ missile capabilities and still uncertain and unpredictable nature of North Korean leader Kim Jong Un, we cannot afford to wait possibly a decade for a new and still conceptual kill vehicle,” he said, noting he hopes the decision to cancel the contract was not "shortsighted."

Alaska Republican Rep. Don Young does not serve on any defense-related House committees but has long touted the importance of Alaska's involvement in national defense.

"With rising global threats from adversaries like North Korea and Iran, it is of utmost importance to our national security that our missile defense systems are capable of defending us," Young said in a statement emailed to the Daily News-Miner.

Young pointed to the importance of the RKV program in ensuring national defense and called the canceled contract "troubling."

"When it comes to our national defense posture, Alaska is an important strategic location for keeping Americans safe," he said. "Our national defense cannot wait for a new kill vehicle program to be developed, and it is one of my highest priorities to see a new kill vehicle swiftly designed and implemented."

All three officials said they plan to look deeper into why the contract was killed.

Contact staff writer Erin McGroarty at 459-7544. Follow her on Twitter: @FDNMpolitics. The Associated Press contributed to this report.