The AGM-158 JASSM’s origins can be traced back to Northrop’s development of the AGM-137 TSSAM, but the Navy and Air Force ultimately chose the JASSM.

The original plan was for the AGM/MGM-137 Tri-Service Standoff Attack Missile to equip the B-52H, B-1, B-2, F-16 and F/A-18 in the Air Force and Navy, and in parallel, M270 ground launchers in the Army.

This program ran into technical and financial problems, and eventually the Army withdrew, which led to the cancellation of the program in 1994.

A look at the AGM/MGM-137 TSSAM

The technical characteristics of TSSAM were as follows:

• Length: about 4.3 meters.
• Gross Weight: 2,000 lbs/907 kg.
• Warhead weight: 1,000 lb/450 kg.
• Warhead type: unitary penetrator for the Navy and Air Force and with submunitions for the Army and alternatively for the Air Force.
• Type of guidance: GPS and INS for all three branches, with Air Force and Navy IIR missiles in the final phase.
• Range: greater than 100 nautical miles/185 kilometers.

The development of JASSM

After TSSAM was canceled, the Army went to ATACMS and the Air Force and Navy began development of JASSM. The two industries greatly benefited from TSSAM’s technology.

In the early stages the development of JASSM faced obstacles. In 1999 JASSM test flights began and in 2001 production of the first batches began. The problems appeared from 2003 onwards, with improvements and testing completed in 2009.

The AGM-158 JASSM

In general, JASSM is a long-range and low-cross-section radar cruise missile. So far it is certain that it will be in the arsenal of five countries. Specifically, outside the US, users include Australia, Poland, Finland and in the future Germany.

In its basic version as the AGM-158A JASSM, it bears enormous similarities to the TSSAM. Same overall weight, weight and warhead type but has a longer range (370km).

At the same time, it uses GPS and INS for guidance with the possibility of using an IIR searcher in the terminal phase. Using this achieves a CEP of less than 3 meters and 13 meters with GPS and INS alone.

AGM-158B JASSM-ER (Extended Range)

JASSM-ER is an improved version of JASSM, the development of which started in 2002. Its first tests were carried out in 2006 and the first operational batch was delivered in 2014.

Externally JASSM and JASSM-ER are identical. Their differences are on the inside, with the JASSM-ER having a larger fuel tank and a more efficient turbofan engine as opposed to the turbojet of the “regular” JASSM. This results in a missile range of 926-1,000 kilometers. Finally, it maintains the same guidance methods.

AGM-158C LRASM (Long Range Anti-Ship Missile)

LRASM is a modified version of JASSM-ER, specialized for anti-ship strikes.

Much emphasis was placed on the cruise missile having increased autonomous guidance capabilities to reduce the need for targeting by other platforms.

LRASM uses both a different interrogator, multi-mode RF, and data-link to get data in flight. At the same time, it uses a GPS system resistant to interference, INS, ESM and IIR sensor with the ability to “match” the target in front of it with the image of the one it has stored in the memory.

Although its range is not exactly known, based on the fact that it is a modification of the JASSM-ER but with more weight, it is estimated to be in the range of 500-600 km.

LRASM is already certified on the F/A-18 Super Hornet, B-1B Lancer and is being certified on the F-35, B-52H and possibly the P-8 Poseidon in the future. At the same time it can be launched from vertical launch cells (VLS) Mk41.AGM-158B-2 (Extreme Range)

It is the last known version of JASSM. It has gone through several name changes (AGM-158D, JASSM-D, JASSM-XR). Although not much is known about this version we do know that it will have a new fin design as well as a new coating to further reduce RCS and heat footprint.

At the same time, it will have a greater weight, a larger warhead and a much longer range that will approach 2,000 kilometers.

To Sum Up

The JASSM family is one of the most capable cruise missiles on the market. They are capable of hitting a wide range of targets, from infrastructure to ships. They can be used by fighters, bombers, ships and transports, through the Rapid Dragon.

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