A test of the U.S. military’s Aegis missile defense system in Hawaii appears to have ended in failure on Wednesday, when the SM-3 Block IIA missile launched to intercept failed to connect with a mock offensive ballistic missile launch. This marks the second failure of the Aegis missile defense system in the past year, coinciding with the growing threat of ballistic missile attack from North Korea. The failure has been acknowledged anonymously by several senior officials, though the Pentagon has thus far kept quiet on the matter.

Wednesday’s test involved a ballistic missile armed with a dummy warhead being launched from an aircraft, followed by land based Aegis assets acquiring and tracking the missile before firing a Raytheon-built SM-3 Block IIA ballistic missile on an intercept course.

A similar test conducted in July ended in failure as well, though the Department of Defense reported that it was the result of human error, rather than an issue with the system. According to their statement at the time, a sailor aboard the guided missile destroyer USS John Paul Jones erroneously identified the ballistic missile threat as “friendly,” forcing the SM-3 launched from the ship to self-detonate prematurely.

This time, however, the Pentagon isn’t even acknowledging the test took place.

“The Missile Defense Agency and US Navy sailors manning the Aegis Ashore Missile Defense Test Complex (AAMDTC) conducted a live-fire missile flight test using a Standard-Missile (SM)-3 Block IIA missile launched from the Pacific Missile Range Facility, Kauai, Hawaii, Wednesday morning,” defense spokesman Mark Wright said when asked about the test. Despite his glossing over the attempted intercept, his statement has actually been the most forthcoming to come out of the Defense Department thus far.

Of course, with rumors of a North Korean military parade intended to highlight their growing suite of Hwasong-15 intercontinental ballistic missiles expected to occur before the start of the Olympic Games in South Korea later this month, it’s possible the U.S. would simply prefer to keep these failures close to the chest.

This test was unusual compared to previous intercept launches, primarily because it relied on shore-based Aegis assets – a missile defense platform developed for use on military ships. The United States employs the Aegis system on warships throughout the Pacific as a part of a three-fold missile defense infrastructure intended to intervene after an offensive launch from an aggressive state like North Korea from ever reaching American, or allied, shores.

The other two elements of this missile launch safety net include the powerful radar-based THAAD system recently deployed in South Korea to the chagrin of the Chinese, and America’s troubled GMD missile defense system here in the United States. The GMD program has also suffered a series of failures and “conditional” successes in recent years.