Japan approves purchase of AGM-158B JASSM-ER for its F-15J

When paired with JASSM-ER missiles and related electronic, optical, radar and satellite surveillance systems, the JASDF F-15J fighters will also be able to perform stand-off strikes.

The Japanese Ministry of Defense approved the purchase of the Lockheed Martin AGM-158B JASSM-ER (Joint Air-to-Surface Standoff Missile-Extended Range) missile on July 4, 2024, based on a Foreign Military Sales (FMS) package approved by the U.S. Department of State on August 28, 2023. Under the program, Tokyo will purchase 50 JASSM-ER missiles as a long-range land-strike weapon to be used by F-15J aircraft of the Japan Air Self-Defense Force.

The reports say the MoD “plans to drastically enhance its stand-off defense capabilities,” which will allow it to strike from outside the range of enemy anti-aircraft missiles. Tensions between the U.S.-Japan-Taiwan alliance and the China-Russia-North Korea group have been consistently high for the past two years. The State Department’s FMS approval, which also includes a global anti-jam positioning system, missile containers and training missiles, is worth $104 million.

Our JASSM-ER delivers the extended range precision needed in today’s modern defense: https://t.co/P3oiFnrCRt photo:twitter.com/TRPAHiF8Ph

— Lockheed Martin (@LockheedMartin) April 25, 2016

Modernized F-15J and JASSM

“The upgraded F-15s equipped with this missile will have improved electronic warfare capabilities and an increased number of missiles,” the report said. “Further upgrades will be made to the 68 aircraft that have already been upgraded.”

The mention of the electronic warfare capabilities of Japan’s F-15J fleet refers to a $475 million contract signed by Boeing under the F-15 Japan Super Interceptor program in September 2023. The program involves the integration of the Eagle Passive Warning Survivability System (EPAWSS) into Mitsubishi’s F-15Js, which allows the aircraft to detect and engage ground and air threats while enhancing situational awareness.

When combined with JASSM-ER missiles and allied electronic, optical, radar and satellite surveillance systems, the JASDF F-15J fighters can now conduct stand-off strikes in dynamic and changing battlefield situations where targets require rapid action.

Leading Air Launched Missile

JASSM is becoming the mainstay of allied air-launched land-attack weapons, with Poland and Finland among the latest countries to acquire the Extended Range variant. On May 28, 2024, the Polish government signed an agreement to buy another batch of JASSM-ER missiles under a $735 million contract for 821 missiles, and last year it also expressed interest in the JASSM-XR missile.

Then on May 31, Finland announced the acquisition of AGM-158B JASSM-ER missiles to be integrated onto F-35A aircraft, which are to be delivered by 2026. Helsinki already operates AGM-158A JASSM missiles, which are carried by Finnish Air Force FA-18C/D Hornet aircraft.

JASSM is also the weapon of choice for the USAF’s Rapid Dragon project. The program calls for the missiles to be packed into disposable pallets by both the C-130J Hercules and the C-17 Globemaster III, which are released from ramps and then eject groups of missiles. The service has tested this palletized missile drop on several occasions, including during an exercise in the Western Pacific in July 2023.

In mid-June, the 2nd Bomb Wing USAF (U.S. Air Force) at Barksdale AFB, Louisiana (Air Force Base), conducted Exercise Bayou Warrior, during which active JASSMs were loaded onto a B-52H Stratofortress strategic bomber as part of a readiness exercise. The exercise tested the wing’s ability to “generate, load, and deliver conventional weapons in a simulated environment,” emphasizing the logistical, non-combat, and technical elements of overall combat support.

3/ “During stabilization and parachute descent, this new deployment system sequentially released multiple JASSM-ER mass simulators and demonstrated the ability to safely deconflict the airspace between weapon launch intervals.” photo:twitter.com/dkXhBgpWr7

— Guy Plopsky (@GuyPlopsky) August 20, 2021

JASSMs

JASSM is a Low Observable (LO) missile that deploys its folded wings after being dropped from a launch aircraft. The weapon is capable of following predetermined routes to targets set on the ground before launch and changing directions to avoid and disorient enemy Air Defense (AD) missiles. The turbojet-powered missile has a range of 370 km and carries a 450 kg WDU-42/B penetrating warhead.

Meanwhile, the AGM-158B JASSM-ER, according to CSIS (Center for Strategic and International Studies) is powered by a turbofan engine and can reach distances of up to 1,000 km.

The missile is guided by an INS/GPS unit developed for the JDAM and JSOW bombs, and also uses an IR seeker for final guidance. JASSM includes 3D targeting models of intended targets, eight of which can be stored in each missile. The Air Force indicates that the missile is accurate to within 3 meters of CEP (Circular Error of Probability).

Purchases of Japanese Rapid Dragon missiles and long-range missiles

In August 2023 Japanese Times said the MoD was also considering “fitting long-range missiles” on its 15 C-2 transport aircraft to “improve long-range defence capabilities”. “The missiles could be used to strike enemy bases such as missile launch sites in counter-attack operations (and) the MoD is considering using a type of missile whose engine ignites in mid-air after the missile is dropped,” the report said.

The report also made reference to the USAF’s Rapid Dragon project, mentioning that “the United States is developing related technology.” It then mentioned that the JASSM was to be introduced on F-15 fighters.

In addition to the JASSM, the MoD also announced in January 2024 a deal with Norwegian defence giant Kongsberg, on 18 October 2023, for the purchase of the JSM (Joint Strike Missile). According to the 2024 budget request document, the missiles are to be delivered by 2026 and integrated with the JASDF F-35A. The JSM is an air-launched version of the NSM (Naval Strike Missile).

JASSM cannot be placed in the F-35A’s internal weapons bay. Instead, it would have to be carried on the Lightning II’s external mounting points, which would expose the aircraft to low observability.