A $585 million contract has been awarded to Lockheed Martin to design, develop and deliver a big Homeland Defense Radar- Hawaii by 2023 for added defense against North Korean and other advancing missile threats.

By the time it is fully operational, the radar, which may be built on Kuaokala Ridge at Kaena Point, is expected to cost about $1 billion.

Lockheed said in a release Tuesday that it will leverage the development of a long-range discrimination radar under construction in Clear, Alaska, “to provide the lowest risk and best value” radar for Hawaii using a scalable architecture for future growth.

Kuaokala Ridge is adjacent to the Air Force’s Kaena Point Satellite Tracking Station; two sites at the Army’s 9,500-acre Kahuku Training Area also are being examined.

Much of the planning attention is focused on Kaena Point. An environmental impact statement analysis of all three sites is still underway.

The radar will be used to track what are expected to be increasingly complex ballistic and hypersonic missile threats to Hawaii from North Korea, China and Russia.

The nonprofit Missile Defense Advocacy Alliance said the United States is pursuing hypersonic missiles to deliver conventional payloads, while China and Russia plan to equip hypersonic missiles with conventional as well as nuclear warheads.

Rear Adm. Jon Hill, deputy director of the Missile Defense Agency, said at a Hawaii presentation in June that the missile threat “continues to grow, no matter what region you are in.”

Hawaii will always be a militarily strategic site in a strategic location, Hill said, adding the United States wants to keep pace defensively with the missile advances.

He said that as a result of an analysis of alternatives, “we determined that we needed another radar in this area in order to detect out as far as we can to discriminate as far as we can,” primarily for ballistic missiles.

Discrimination refers to the ability to differentiate warheads from rocket debris and decoys.

Hawaii is protected by 44 ground-based interceptor missiles in Alaska and California, and the new radar will help with advancing threats, he said.

The Homeland Defense Radar-Hawaii will not be in a dome. Instead, it will have an angular, blocklike shape with a radar face that’s estimated to be 60 to 80 feet tall and 30 to 50 feet wide, Hill said.

Approximately 160 acres of mostly state land at Kuaokala Ridge would be used for the radar, which will identify, track and classify long-range ballistic missile threats in the midcourse of flight.

The facility will have communications equipment to transfer data to a fire control system for the interceptor missiles in Alaska and California and provide ballistic missile defense for Hawaii and the mainland.

Also planned are entry control and maintenance facilities, water supply and treatment buildings, and an electrical substation.

Lockheed Martin released an artist’s rendering of what the facility could look like, but the Missile Defense Agency said the final configuration of the site had not been determined.

Construction is expected to start in 2021, with initial operating capability late in 2023.