SM-6 SBT Sea-Based Terminal
The Aegis Combat Management System (CMS) is broken down into IA/B and RIM-174 SM-6 Dual-I/II weapons. The SM-6 missile system was originally conceived to perform AAW missions at extended and over-thehorizon ranges using an active seeker that requires no remote terminal illumination of the target. The extended-range capability increases the Aegis Weapon System’s battlespace to counter adversaries before they become an imminent threat to friendly forces. Fortuitously, as the capabilities of the SM-6 weapon began to be fully realized, the concept of using this missile system in multiple missions emerged. For example, the use of SM-6 for BMD missions was demonstrated as part of the Sea-Based Terminal (SBT) program to counter ballistic missile threats in endo-atmospheric regions.
SM-6 Dual-I ARH/SARH SAM which has 130nm (240km) range and uses a power- enhanced capability to intercept IRBMs,
Aegis BMD continues to demonstrate a capability to intercept non-separating, simple-separating, and complex-separating ballistic missiles in the midcourse phase of flight with SM-3 missiles. Aegis BMD has also demonstrated a capability to intercept select ballistic missiles in the terminal phase of flight with SM-6 missiles. However, flight testing and M&S have not addressed all expected threat types, ground ranges, and raid sizes. The MDA has used M&S to explore Aegis BMD raid engagement performance, but DOT&E has less confidence in these results because COMOPTEVFOR has been unable to accredit the models due to the lack of validation data from live fire raid engagements and lack of post-intercept debris modeling.
MDA ground tests have routinely shown that inter-element coordination and interoperability need improvement to improve engagement efficiency; however, flight testing with multi-element engagement coordination has been limited. Aegis BMD has exercised rudimentary engagement coordination with Terminal High-Altitude Area Defense firing units, but not with Patriot. The MDA planned to exercise engagement coordination between those three theater elements during Flight Test Operational (FTO)-05, but that flight test had been repeatedly delayed and as of 2020 was planned for FY28. DOT&E and USD(R&E) prompted the MDA to establish a ground testing approach to support assessments of missile reliability. DOT&E cannot assess SM-3 missile reliability with confidence until the MDA is able to provide additional ground test data that simulate the in-flight environment.
In December 2016 MDA conducted a detection, tracking, and intercept test (FTM-27) to further assess the capability of Sea Based Terminal Increment 1 in the Aegis Baseline 9.C1 (BMD 5.0CU) Weapon System. During this test operators fired a salvo of two SM-6 Dual I missiles against the MRBM target launched out of PMRF. In Flight Test Aegis BMD (FTM)-31 Event 2 (August 29, 2019) MDA and the Navy successfully intercepted an air-breathing target with a Standard Missile-6 (SM-6) Dual II in anti-air warfare mode. This engagement supports the SM-6 Dual II Engineering Change Proposal production decision and subsequent delivery of interceptors to the fleet.
Sea Based Terminal Increment 2, which further improves endo-atmospheric defensive capabilities, was on schedule to be certified and operational in the 2018-2019 timeframe. MSA conducted a successful Critical Design Review in March 2016 for the SM-6 Dual II Sea-Based Terminal defense interceptor and conductrf missile and weapon system integration testing in 2017.
The first intercept flight test supporting Sea Based Terminal Increment 2 was planned for first quarter of FY 2019. The coronavirus (COVID-19) pandemic caused a 6 month or greater delay to Aegis BMD’s first ICBM intercept attempt, FTM-44, and to the first SBT Increment 2 flight test in BMD Initialized mode, FTM-31 Event 1 (E1). The MDA conducted FTM-44 in November 2020 and planned to conduct FTM-31 E1 in April 2021.
Aegis BMD participated in two non–intercept flight test events in FY20 with live ballistic missile targets and an HGV. During Flight Test Experimental Other (FEX)-01 in March 2020, an Aegis BMD destroyer engaged a hypersonic glide vehicle (HGV) with a simulated SM-6 Dual II missile. The AN/SPY-6(V)1 Radar participated in the event.
The U.S. Missile Defense Agency, in cooperation with the U.S. Navy, conducted Flight Test Aegis Weapon System 31 Event 1 on 29 May 2021. The objective of the test was to demonstrate the capability of a ballistic missile defense (BMD)-configured Aegis ship to detect, track, engage and intercept a medium range ballistic missile target with a salvo of two Standard Missile-6 Dual II (BMD-initialized) missiles. However, an intercept was not achieved.