The Missile Defense Agency aced a test Monday night of its long-range SM-3 Block IIA interceptor, with the defensive missile, fired from the Aegis Ashore complex on Kauai, striking an intermediate-range ballistic missile target launched “thousands” of miles away to the southwest.

The successful test was a retry of a Jan. 31 failed intercept.

The flight also demonstrated the Aegis Weapon System’s “engage on remote” capability to track and intercept enemy missiles using a network of radars and sensors — possibly including an F-35 Joint Strike Fighter.

Agency Director Lt. Gen. Sam Greaves said the test has “great significance” for the future of what’s known as “multi-domain” missile defense in which increasingly sophisticated long-range missiles are being fielded by China, Russia, Iran and North Korea.

A $1 billion long-range radar is planned for Oahu to assist in countering the missile threat.

Monday’s test also paves the way for deployment of Raytheon’s SM-3 Block IIA to Poland, where an Aegis Ashore facility is intended to help protect Europe.

“This system is designed to defend the United States, its deployed forces, allies, and friends from a real and growing ballistic missile threat,” Greaves said in a release. “I offer my congratulations to all members of the team, military, civilian, contractors and allies who helped make this possible.”

The first successful intercept of an intermediate-range ballistic missile target by the SM-3 IIA proved out an “Iran to Europe” or “North Korea to Guam” range defense, said Riki Ellison, chairman of the nonprofit Missile Defense Advocacy Alliance.

The test fused multiple sensors and radars from space, air, land and sea to give the best firing solution to the new SM-3 IIA, an interceptor that is capable of flying beyond the range of the sensor platform it is launched from, Ellison said in a release.

Available sensors may have included the F-35 Joint Strike fighter, MQ-9 Reaper unmanned aerial vehicle and Sea-Based X-Band Radar, Ellison said.

The ballistic missile target was air-dropped from an Air Force C-17 cargo plane “from the broad ocean area thousands of miles southwest of the Aegis Ashore” test site, and from there the missile’s rockets ignited, sending it on its path looping through space, according to the agency.

In October the Missile Defense Agency scored a hit — and a bit of renewed confidence — after an SM-3 IIA fired from the Pearl Harbor destroyer USS John Finn impacted a medium-range ballistic missile target off the west coast of Kauai.

The SM-3 IIA guided missile is being developed cooperatively by the United States and Japan and is part of what was originally the Aegis ship-based ballistic missile defense system but now has moved onto land as well.

The missile’s improved range over the SM-3 Block IB has the United States eyeing it for the future defense of Hawaii and for Japan’s land- and sea-based defense against North Korean or Chinese missiles.

A medium-range ballistic missile is defined as traveling between 620 and 1,860 miles. An intermediate-range ballistic missile flies between 1,860 and 3,418 miles. Missiles that travel even farther through space are defined as intercontinental ballistic missiles, or ICBMs.

Guam is about 2,100 miles from North Korea, while Hawaii is about 4,660 miles from the nuclear-armed nation.

Monday’s test follows a Jan. 31 failure off Kauai when an SM-3 IIA did not intercept an air-dropped intermediate-range target missile. A “hybrid arm and fire device” — essentially a spark plug — did not ignite the third-stage rocket, an agency investigation determined.

The SM-3 IIA costs $36 million per missile, while the target missile cost about $40 million, the Missile Defense Agency previously said. The entire Jan. 31 test cost about $130 million.

The Jan. 31 flight test was the first time an SM-3 IIA missile was launched from land using the Aegis Ashore test complex on Kauai. The Missile Defense Agency said it plans to test the SM-3 IIA against ICBM-range missiles in the future.