On July 24, the Missile Defense Agency (MDA) indicated that sailor error was responsible for a failed SM-3 Block IIA missile intercept test. According to Defense News, a tactical datalink controller, responsible for maintaining communications between the missile and the Navy’s Aegis ship combat system, incorrectly identified the incoming ballistic missile target as friendly, consequentially initiating the interceptor’s self-destruct protocol.

Although the review is still ongoing, MDA director Lt Gen Samuel Greaves has said “the SM-3 IIA interceptor and Aegis Combat System have been eliminated as the potential root cause,” of the failure. The June 22, 2017 test was the fourth flight test of the SM-3 IIA, and the second intercept. The SM-3 IIA’s first intercept test in February 2017 was a success.