JSOW!

Short range air defenses (SHORAD) have traditionally been the likeliest ground based weapons to shoot down attacking aircraft. En route to a target, strike aircraft can either bypass or fly above most air defenses. Longer ranged Surface to Air missiles systems can be jammed, suppressed, spoofed, or simply outmaneuvered. But the defenses right at the target? You have to face them. Worse, they tend to be the cheapest systems around, guns and short ranged missiles, so losing a $40 million jet to a $20,000 missile is a poor trade, even if you do manage to successfully attack critical targets.

Common sense tells us that almost anything we can do to keep planes outside of the terminal defenses, and still strike the target, is worth doing. That’s the whole idea behind almost every surface attack guided missile ever built. But the history of surface attack missiles hasn’t always been one of unalloyed joy. I mean, there’s a reason they call them “missiles” and not “hittiles”. Missiles have typically been far more expensive than conventional unguided munitions, and their accuracy and lethality has often been lacking.  For instance, the AGM-12 Bullpup could usually be counted on to hit the ground. But its small warhead and lack of precision meant that it couldn’t really be counted on to destroy small hard targets such as bunkers or bridges.

Finally, in this age where electronics have become far more compact, reliable, and less costly, and the GPS system has become enmeshed in everyday life, we’ve reached a point where missiles are, for so many mission, the weapon of first resort.  The biggest revolution has arguably has come from the combination of GPS guidance with inexpensive, but highly accurate inertial navigation system platforms.  The poster child for this GPS/INS pairing is the JDAM, or Joint Direct Attack Munition, a bolt-on kit that converts dumb bombs into precision guided weapons.

But JDAM has a fairly short range. To keep an attacking aircraft out of SHORAD range, a little more standoff is needed. Indeed, a precision standoff weapon would often be used for the mission of SEAD, or Suppression of Enemy Air Defenses. The AGM-88 anti-radiation missile can knock back enemy radars, but leaves the rest of a site unimpaired. A follow on punch is needed. And that punch often takes the form of the AGM-145 Joint Stand Off Weapon, or JSOW.

The concept behind the JSOW was to use a single airframe and guidance architecture that would serve as a “truck” to carry a series of different warhead payloads.  The weapon is roughly 1000 pounds, and looks like a slightly squared bomb shape.  A pair of pop-out wings let the JSOW glide from the launch point to the target, with a range of about a dozen miles when launched from low altitude and up to sixty miles when launched at higher altitudes.

The original plan was to build three variants:

  1. AGM-145A- with BLU-97 Combined Effects Munition bomblets that would be used to attack area targets such as missile batteries, assembly areas, artillery batteries and troop areas.
  2. AGM-145B- armed with the BLU-108 “Skeet” smart anti-armor munition to attack columns of armor.
  3. AGM-145C with a 500 pound unitary warhead to attack hardened targets such as bunkers.

The demise of the Soviet Union meant the threat of massed armor attacks was greatly lessened, and the “B” model was not developed. The “A”  model entered service in the late 1990s, and was used in combat for the first time in 1998. The  “C” model entered service in 2005.

Originally, the “C” model was to use the BLU-111 warhead, which is basically the ‘splodey part of the Mk82 500 pound bomb, but its limited penetration lead to the “C” using the BROACH warhead instead. The BROACH uses a two-stage warhead, with a large shaped charge blasting a hole through which the main explosive charge follows to explode inside. Army types may recognize this technique from the 40 pound cratering charge.  GPS/INS guidance is accurate to within just a few meters, but for attacks against discrete targets such as bunkers, you need something more precise still. Accordingly, the “C” model uses its GPS/INS to navigate to the target, then uses an imaging infrared (IIR) seeker with autonomous guidance to provide terminal guidance.

Concerns over unexploded ordnance and the fact that many foreign nations are signatories to a ban on cluster munitions is leading to a development of an “A” model armed with the BLU-111.

The JSOW can be launched in a “pre-briefed” mode, where the target coordinates are loaded before launch, or a Target of Opportunity mode, by designating the target via the launching aircraft onboard radar or other sensors.  The Navy uses the JSOW on it’s F/A-18C and E/F Hornets and Super Hornets. The Air Force uses it from F-16s, F-15Es, B-52s, B-1s, and B-2 bombers. Both services will use it with the F-35 fighters.

While the JSOW hasn’t been called upon much in our wars in Iraq and Afghanistan, they could well be critical in future campaigns. Let’s imagine tensions continue to rise with Iran, and a strike against critical facilities is called for. Losing an airplane and having its crew become prisoners of the regime is unacceptable.   Carrier based F/A-18s with AGM-88 HARMs would knock back long range air defense systems, while others used JSOW-As to keep them down and suppress guns and short range missiles in the target area. Air Force F-15E Strike Eagles launching JSOW-Cs from high altitude make the actual strike on the target.  The standoff range of the JSOW means the strike could reach 60 miles into Iran without any aircrew ever even crossing the beach. For strikes further inland, more JSOWs could be used to blast a corridor through the Iranian defenses, greatly reducing the risk of losing an aircraft.

This is a pretty long post considering that the original impetus was that I wanted to share the ‘splodey video below with Roamy.

[youtube=http://www.youtube.com/watch?v=eBMy4Cp0kpY&w=448&h=252&hd=1]

4 thoughts on “JSOW!”

    1. The Air-to-ground capability of the AIM-9X is from tweaking the software of the seeker. It simply adds a mode to the missile. Any changes to the missile are likely software only.

      If I had to guess, the terminal IIR seeker of the JSOW-C is the WGU-10/B of the IIR Maverick. It and variants of it have been used on several weapons.

  1. Interesting info. I hope our “pals” overseas don’t read your blog. . .Not that there is anything but open source material here. . .

    1. N/O, I’m very careful about OpSec. In fact, the one time I met NepLex, we spent a good deal of time discussing that topic in regards to blogging. I don’t have access to anything but open source literature, but I also try not to tout too loudly certain aspects of TTP that, while in the public domain, aren’t widely known.

      And yes, people overseas, including specifically Iran, do read this blog.

Comments are closed.