(Update: U.S. Central Command has and stated that, a , the missiles used in the Syria strikes were the original, shorter range version of JASSM, not JASSM-ER. Regardless, it is still the first time any JASSM variant was used in combat.)
One of the missiles used in last week’s strike on Syrian chemical weapons facilities was a new weapon seeing its first taste of combat.
It's called the Joint Air-to-Surface Standoff Missile-Extended Range. The weapon could use a real name, but in the meantime you can call it JASSM-ER. The missile is one of the most advanced conventional weapons in the U.S. arsenal and is currently being modified to attack targets at sea.
The U.S. Navy and Air Force unleashed 57 long-range missiles at the Barzah Research and Development Center, home to the Syrian government’s chemical weapons development program. Each of the 57 packed a half-ton high explosive warhead. Despite Russian claims to the contrary, it appears all 57 missiles hit their mark, doing considerable damage to a Syrian chemical weapons program that has been repeatedly used against rebel civilians.
Nineteen of the missiles that struck Barzah were JASSM-ER missiles. Despite the U.S. military’s recent air campaigns over Syria, Iraq, Somalia, Afghanistan, and Libya, JASSM has never been used in combat. The lack of meaningful air defenses over those battlefields meant that a sophisticated missile like JASSM was unnecessary—until now.
The AGM-158 JASSM was originally a Navy-Air Force program to develop a low-observable cruise missile capable of penetrating heavily defended enemy airspace and destroying high-value targets. Through the use of a stealthy airframe, low-altitude ground-skimming flight, and the ability to fly around known enemy defenses, JASSM was a “day one” weapon capable of attacking targets on the very first day of an air campaign before enemy air defenses were shut down.
The B-1, B-2, B-52H, F-15E, and F-16 can all carry JASSM. The B-1 can carry up to 24 missiles at a time, loaded on rotary launchers and dropped out of the bomb bay. Although the U.S. used two B-1s during the Barzah strike, it could have used just one bomber. (The second bomber was likely a backup plane flying shotgun in case the primary bomber had to return to base before launching her missiles.) Just five B-1 bombers could have carried out all the missile strikes—U.S., French, and U.K.—with missiles to spare.
The original version, JASSM, first flew in 1999 and was declared operational in 2003. It was powered by a Teledyne Technologies J402 turbojet engine, which pushed the 14-foot-long cruise missile at subsonic speeds to distances of just over 200 miles. The missile’s 1,000-lb. warhead is armed by a hard target smart fuse that aids in penetrating underground or concrete structures, allowing the blast effects of the warhead to reach the high-value leadership targets, weapons, chemical agents, or other items protected inside.
Here's a Lockheed Martin video of JASSM blowing up things:
Once launched from an aircraft, JASSM typically flies a flight path chosen ahead of time, allowing the low-flying missile to mask its approach to target with terrain such as hills, valleys, and mountain ranges. The missile can be programmed to fly around known air defenses such as S-400 “Triumph” radars and missile batteries, using an internal navigation system and jam-resistant GPS to find its way around. Near the target, JASSM switches on its imaging infrared seeker to automatically recognize its target and home in for a kill. JASSM is capable delivering its warhead to within three yards of its target.
JASSM was an excellent missile but a range of 230 miles, coupled with long, looping flight profiles to evade enemy defenses could mean carrier aircraft had to fly relatively close to the target. That could put the aircraft within range of enemy fighter jets or enemy air defenses. Thus was born the AGM-158B JASSM-ER, with -ER standing for “Extended Range”. Using a Williams Intl. F107-WR-105 turbofan engine, JASSM-ER is capable of flying more than 500 miles, increasing the margin of safety for a large bomber or small fighter with two large cruise missiles hanging off its wingtips.
The rise of the Chinese and Russian navies, as well as a lack of a modern U.S. Navy anti-ship missile, prompted developer Lockheed Martin to modify JASSM-ER into a ship-killer. The AGM-158C Long Range Anti-Ship Missile (LRASM) features increased autonomous capability. The missile is capable of sensing enemy air defense radars on ships and flying around them to reach its target. It can also coordinate mass attacks so that multiple missiles arrive on target from many directions at the same time, overwhelming enemy defenses.
LRASM will launch from U.S. Navy destroyers, cruisers, and F/A-18 Super Hornet strike fighters. Air Force B-1 bombers will carry up to 24 of the anti-ship missiles.
The sophisticated nature of the AGM-158 series missiles (JASSM, JASSM-ER, and LRASM) mean they won’t be used very often. If and when they are used it basically means something very bad has happened. While it’s useful to have such capable missiles in U.S. arsenals, let’s hope they stay there.