WASHINGTON — The U.S. Army’s major missile defense command system, which has been in development for years and experienced lengthy delays, successfully completed a complex test Dec. 12 against two cruise missiles, marking the last hurdle to get the system ready for its operational test next year.

The service planned to up the ante in the December test as a last effort to prove the capability of the Integrated Air and Missile Defense Battle Command System, or IBCS, ahead of a limited-user test in the third quarter of fiscal 2020, Brig. Gen. Brian Gibson, who leads the Army’s air and missile defense modernization effort, told Defense News in October.

The IBCS has journeyed a rocky road to a delayed fielding, partly after failing its first limited-user test in 2016.

Software problems discovered during that first test resulted in schedule delays of nearly four years. The Army originally planned to reach initial operational capability in FY19, but those plans slipped to the third quarter of FY22, according to FY18 budget documents.

But the system, which is meant to tie together all missile defense sensors and shooters on the battlefield through a command-and-control center, has seen recent success in its testing program.

According to the manufacturer of IBCS, Northrop Grumman, the system was able to simultaneously track and engage two incoming target cruise missiles during a flight test at White Sands Missile Range, New Mexico.

Adding to complexity the threat-representative cruise missiles flew in a maneuvering formation until nearing targets and then “split off to attack two separate defended assets,” the company said in a statement.

The IBCS system was tied to the Sentinel radar, the Patriot air defense system and a Marine TPS-59 radar connected through an external Link 16 network, demonstrating the system’s ability to tie into joint systems and Army-specific systems.

An F-35 fighter jet with sensors adapted for IBCS also contributed to the test.

Patriot Advanced Capability-2 Guidance Enhanced Missile-TBM interceptors were used to take out the targets in the test.

Northrop said the test “demonstrated successful interoperability and the end-to-end performance of the IBCS system to detect, track and simultaneously engage multiple threats.”

The test “further demonstrates the maturity of the Integrated Battle Command System and its capabilities in support of Multi-Domain Operations,” Maj. Gen. Rob Rasch, the Army’s program executive officer for missiles and space, said in the Northrop statement. “The inclusion of Marine Corps and Air Force sensor systems in the test architecture validate the system’s open architecture and the potential for IBCS to operate seamlessly with joint services, as well as foreign partners in the future, to extend battlespace and defeat complex threats."

Gibson told Defense News shortly after the test that it marked the involvement of the highest number of soldier operators in an IBCS developmental test to date. The Army has worked to keep the same unit involved — a test detachment from the 30th Brigade, 3rd Battalion, 6th Air Defense Artillery Regiment — in recent tests to build confidence and entrenched knowledge in the system.

The test also proved the system isn’t just useful to the Army, but could be a joint system, as it worked to tie in a Marine Corps ground radar as well as aerial sensors on an Air Force fighter jet, Gibson explained.

The Army is still on the same path toward a limited-user test, Gibson added, and he expects it to begin in late spring or early summer. Afterward, the Army will make a decision on the way forward for IBCS in the late summer or early fall.

Gibson said he feels more prepared for the limited-user test as the result of the recent developmental tests of the IBCS system, adding that the test results put to rest the technical risk that previously existed.

While the initial fielding will involve tying together the Army’s primary air defense sensors — Sentinel and Patriot — it’s just a launching pad for broader fires integration across the Army and potentially the joint force, Gibson said.