A Japanese navy warship fired an anti-air RIM-162 Evolved Sea Sparrow Missile (ESSM) towards a simulated target during training with the US Navy (USN) last week in Hawaii amid rising tensions with China in the western Pacific.
A naval clash with China in the East China Sea near the Ryukyu islands and Okinawa has long been assessed to be a likely scenario, especially during a Chinese military move on Taiwan.
Whether Tokyo and Washington might actually participate in counter ops in support of Taipei remains to be seen; however, any single force taking on a logistically superior China has little chance of success, with only a combined force having the potential to pose a serious challenge to the People’s Liberation Army Navy (PLAN) and PLA Air Force (PLAAF).
Missile Firing With An Eye On China
Photos showed the Japan Maritime Self-Defense Force (JMSDF) JS Suzutsuki destroyer releasing the missile from a vertical launch silo (VLS). It is not clear if an expendable target drone was used for the missile to hit or if the firing was to practice other aspects of war.
A statement by Japan’s Ministry of Defense (MoD) described the JS Suzutsuki as being “currently on dispatch training to the US” that conducted a “launch training of the ESSM…in the surrounding sea of Hawaii in support of the US Navy.”
The operative word, “in support,” indicates clear interoperability between the Japanese and American navies. Japan Maritime Self-Defense Force (JMSDF) warships can be assumed to be part of a combined fleet providing integral air defense to US Navy (USN) vessels, who might undertake larger anti-shipping or even land attack fires.
The Commanding Officer of JS Suzutsuki, Commander Noguchi Yuta, said, “We managed to display the full capability of our installed weapon systems, succeeded in defeating a target, and improved our tactical capabilities. In addition, crew morale is high to respond to new missions.”
That the target is China’s People’s Liberation Army Navy (PLAN) was reflected in Cdr Yuta’s subsequent statement describing the broader objectives. “(It is to realize) of a Free and Open Indo-Pacific and a security environment that does not tolerate any unilateral attempts to change the status quo by force,” Yuta was quoted in the JaMoD statement.
Other Drills Between US & Japanese Navy, Air Force
Also, in what appears to be a response to Chinese and Russian H-6 and Tu-95 strategic bombers conducting joint patrols over the Sea of Japan and the East China Sea, the US Indo-Pacific Command (INDOPACOM) tweeted pictures of Japan Air Self-Defense Force (JASDF) F-16s flying with US F-35s and an air refueling tanker aircraft.
The “formation” flight “demonstrates the interoperability of our forces and US commitment to supporting a #FreeAndOpenIndoPacific,” the INDOPACOM tweet said.
?: A1C Alexis Redin pic.twitter.com/qZNT8waGvC
— U.S. Indo-Pacific Command (@INDOPACOM) June 24, 2023
Prior to that, on June 20, the JMSDF shared pictures of its Maya-class destroyer, JS Haguro, participating in a bilateral Ballistic Missile Defense (BMD) exercise with the USN’s USS John Finn. The John Finn is a part of the US 7th Fleet.
The Evolved Sea Sparrow Missile
RIM-162 ESSM is a variant of the RIM-7 Sea Sparrow missile (SSM), a sea-launched version of the AIM-7 Sparrow air-to-air missile (AAM) that was created in response to the advancements of the late 1950s.
Interestingly, developing the sea-launched version of the AIM-7 AAM itself was in response to the sinking of the Israeli destroyer INS Eilat in 1967 by a Russian anti-ship cruise missile.
In 1968, four countries (Denmark, Italy, Norway, and the United States) signed a memorandum of understanding (MoU) to jointly develop the NATO Seasparrow Surface Missile System (NSSMS). The NATO Seasparrow Consortium was subsequently born and has now grown to 12 countries.
Japan is among six other non-signatories to the Consortium that has acquired the system. It is installed onboard the Hyuga helicopter carriers, Akizuki, Takanamim, and Murasame-class frigates and fired from Mark 41, 48, and 29 launchers. JS Suzutsuki, from which the ESSM was fired in Hawaii, belongs to the Akizuki-class destroyers.
“In April 1991, the NATO Seasparrow Project Office submitted a proposal to the NATO Seasparrow Project Steering Committee to upgrade the NSSMS to improve performance against faster and more maneuverable low-altitude threats,” according to the Center for Strategic and International Studies (CSIS).
Raytheon then began developing an advanced variant in 1995, aiming to increase the missile’s top speed to Mach 2 and enabling it to perform 30 g maneuvers.
Compared to the RIM-7, the ESSM had midcourse data uplink capabilities, an updated inertial guidance system in addition to its semi-active radar, and a redesigned warhead section.
How The Missile Hunts
The missile is 3.64 meters in length and 0.254 meters in diameter, with a range of around 50 km, is powered by a solid propellant, and can touch speeds of Mach 4.
It employs inertial and semi-active radar for guidance. ESSM guidance systems operate in three different modes: home all the way (HAW), mid-course guidance (MCG) with terminal X-band guidance, or mid-course guidance with S-band uplinked terminal guidance.
In HAW mode, the missile uses semi-active homing from launch to the target. In MCG, the interceptor uses its inertial guidance system to fly to a pre-programmed point when it receives a targeting update from the firing ship.
MCG mode is only available when ESSM is integrated with the Aegis Combat System (ACS), receiving uplinked commands from the AN/SPY-1 radar.
In the Aegis Weapon System variant, an S-band transceiver guides the Aegis SPY-1D S-band radar.
“The missile uses Thrust Vector Control (TVC) to enable tail control, allowing the missile,” which can be presumed to be an arrangement where the rocket exhaust nozzles and the tail fins move together. This allows tighter maneuverability at high speeds for fast-moving targets.