The US Navy Is Getting A Major Radar Upgrade
The first examples of the U.S. Navy’s primary future maritime radar were recently delivered for integration onto two of the U.S. Navy’s newest forthcoming ships, the future Arleigh Burke Flight III guided missile destroyer USS Jack H. Lucas (DDG-125) and the aircraft carrier USS John F. Kennedy (CVN 79). The radar in question is the AN/SPY-6; a modular family of active electronically scanned array (AESA) radars designed to perform a range of wide range of tasks simultaneously. In 2013 Raytheon won the contract to develop a new radar to replace the highly successful AN/SPY-1 series of passive electronically scanned array (PESA) radars.
The AN/SPY-1 has provided the primary sensor for the Aegis combat system on U.S. Navy guided missile cruisers (CGs) and destroyers (DDGs) since 1983. The initial aim of the AN/SPY-6 program was to produce a next-generation sensor to equip the planned next-generation Arleigh Burke—the Flight III—to give it greatly improved threat detection, tracking, and interceptor missile guidance capabilities.
Raytheon beat out Northrop Grumman and Lockheed Martin, the latter of which had submitted a radar that would evolve into the AN/SPY-7, to win this contract in 2013. The Navy took delivery of the first AN/SPY-6(V)1 radar in 2016 and installed it at the Pacific Missile Range Facility (PMRF) in Kauai, Hawaii, where it successfully underwent extensive testing.
As per this original vision, the USS Jack H. Lucas, which is the first of the Flight III Arleigh Burkes, is currently undergoing shipboard integration testing of its combat system, including the AN/SPY-6(V)1. However, since 2013 the U.S. Navy’s requirements for the new radar have grown to include a range of other ships, and so different versions of the system have been developed to meet those requirements.
Fortunately, the AN/SPY-6 was designed to be modular and scalable. Each array is constructed using smaller 2’ x 2’ x 2’ blocks called Radar Modular Assemblies (RMAs), which can be joined together to create arrays of various sizes and shapes to fit different installations. In addition to this flexibility, the RMA design also makes maintenance much easier than for previous generations of maritime radars. If a fault occurs in one RMA, circuit cards inside it can be removed and replaced at sea using only two tools and without affecting the rest of the array. This will reduce downtime when a fault occurs, It also improves the reliability and ease-of-maintenance benefits of a system that also boasts greater mechanical simplicity and the reduction in moving parts that comes with AESA radar technology compared to earlier PESA technology.
The AN/SPY-6(V)1 is the variant that will equip the Flight III Arleigh Burke class DDGs, of which 14 have so far been ordered for the US Navy. Also known as the Air and Missile Defence Radar (AMDR), comprising four fixed arrays with 37 RMAs in each array mounted to the superstructure of the ship. The AMDR also benefits from a new and improved mission system and enhanced power and cooling systems, developed specifically for the Flight III program.
Collectively, the AESA design and improved power, cooling, and mission system capabilities enable the AMDR to detect and track significantly more targets simultaneously than the AN/SPY-1D(V) it is replacing. The huge increase in power output and resolution produces some impressive increases in theoretical detection and tracking range too, although it is worth remembering that in practice detection range against low-flying targets such as anti-ship cruise missiles is generally limited by the radar horizon for ship-mounted arrays. Therefore, the range improvement from the AMDR will likely be greatest against long-range ballistic and hypersonic missiles and missiles with a low radar cross-section that the AN/SPY-1D(V) would struggle to reliably track until they get fairly close.
The AN/SPY-6(V)2 comprises 9 RMAs on a rotating mount which is designed to be installed on a mast rather than directly to a superstructure. Despite its greatly reduced size compared to the AMDR, the AN/SPY-6(V)2 has capabilities that are comparable to the much larger AN/SPY-1D(V) currently found on Flight IIA Arleigh Burkes. It is primarily intended for use on amphibious assault ships, such as the future America class subvariant USS Bougainville (LHA-8), and San Antonio class USS Richard M. McCool Jr. (LPD 29), and for retrofitting onto Nimitz class aircraft carriers. As such, the software for the AN/SPY-6(V)2 has been optimized to provide air traffic control and weather monitoring functions, while remaining capable of adding to the sensor picture and missile guidance channel capacity of a task group in the air and missile defense missions.
A very similar version is the AN/SPY-6(V)3 will equip the future USS John F. Kennedy (CVN 79) and all future Gerald Ford class carriers. It uses the same basic arrays as the AN/SPY-6(V)2, using 9 RMAs, but comprises three separate fixed arrays rather than a single one on a rotating mount. The three arrays are fixed directly to the superstructure on the Ford class CVNs to provide 360-degree coverage, with greater simultaneous coverage capacity than the AN/SPY-6(V)2 and reduced mechanical complexity due to the lack of a rotating mount.
Together, the AN/SPY-6(V)2 and AN/SPY-6(V)3 are known as the Enterprise Air Surveillance Radar (EASR). A major factor in Raytheon winning the EASR competition was the modularity of the AN/SPY-6 radar design and its ability to be readily adapted to different mission requirements. These variants of the AN/SPY-6 are set to steadily replace the larger and less capable long-range AN/SPS-48 and AN/SPS-49 radars on U.S. Navy carriers and amphibious ships as new ones are built and older vessels receive their mid-life refits.
The AN/SPY-6(V)3 has also been selected as the primary sensor for the U.S. Navy’s new Constellation class guided missile frigate (FFG), the first 10 of which were ordered in 2020. The new design combines the EASR, Aegis combat system, and 32 Mk 41 Vertical Launch System cells capable of carrying not only quad-packed RIM-162 Evolved Sea Sparrow Missiles (ESSM), but the same cells can also accommodate the longer-ranged and highly versatile SM-6 and potentially even SM-3 ballistic missile interceptors. As a result, the Constellations will have potent air and missile defense capabilities for a frigate, in addition to their primary anti-submarine and littoral warfare equipment fit. The choice will also ensure that the new frigates benefit from reduced cost and risk by employing a proven design that is already in production for other U.S. Navy vessels.
In a similar vein, Raytheon has also developed a mid-scale variant called the AN/SPY-6(V)4, which pares down the AMDR array that was designed for the Flight III Arleigh Burke from 37 to 24 RMA blocks to create a radar that can replace the existing AN/SPY-1D(V) on the smaller superstructure of existing Flight IIA vessels.
In March 2022, the U.S. Navy awarded Raytheon a contract to begin supplying AN/SPY-6(V)4 radars to slowly replace the AN/SPY-1D(V)s on all the roughly 48 Flight IIA Arleigh Burkes in the fleet as each one comes due for its mid-life upgrade refit. The ‘back end’ power, coolant, and mission systems architecture have also had to be scaled to fit the Flight IIA superstructure, but the result is a much more capable radar that has a high degree of parts commonality with the AMDR array on the Flight III and the EASR on the CVNs, amphibious ships, and the new Constellation class frigates.
Essentially, the U.S. Navy has bet heavily on the AN/SPY-6 family and has signed contracts worth a potential $3.61 billion to start fitting it to all its new surface combatants, and retrofitting it to many existing ones as part of mid-life upgrades. Beyond the obvious cost, risk, and logistics benefits of having an essentially common radar family across the next-generation fleet, the primary motivation for this ambitious program of radar modernization is to counter and stay ahead of evolving threats in the Indo-Pacific.
The AN/SPY-6, as part of the Aegis Baseline 10 combat system, is part of the U.S. Navy’s answer to threats that would include large numbers of missiles coming from different directions at once, at different speeds, altitudes, and with different signatures.
The ability of the AMDR to handle more targets than the legacy AN/APY-1D(V), at greater ranges and with higher track fidelity means that the Flight III Arleigh Burke DDGs will be much harder to overwhelm using the multi-vector saturation attacks. The high resolution and, consequently, target track fidelity should also significantly improve the probability of kill for SM-6 and SM-3 missiles against advanced supersonic and hypersonic anti-ship cruise and ballistic missiles, especially those with terminal maneuvering capabilities.
Furthermore, the improvements are not limited solely to ships actually fitted with the AN/SPY-6 variants. Thanks to the U.S. Navy’s powerful Naval Integrated Fire Control-Counter Air (NIFC-CA) architecture connecting Aegis Baseline 9 equipped vessels with E-2D Advanced Hawkeye AWACS, F-35 Lightning IIs, and F/A-18E/F Super Hornets, even a single AMDR-equipped Arleigh Burke can significantly improve the fidelity of the recognized air and missile defense picture for an entire task group. As the other AN/SPY-6 variants are fitted to more and more vessels, from CVNs to LHAs to FFGs, the collective capacity of a given task group to successfully detect, track and guide threats will dramatically increase.
The U.S. Navy’s radar upgrade program, with the AN/SPY-6 family at its core, may be less visible to casual observers than new aircraft carriers, F-35Cs, or navalized UAVs, but it is nonetheless critical to enhancing the ability of the U.S. Navy to project power in the Indo-Pacific without risking prohibitive losses in the opening hours of any future conflict.
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