Air Weapons: Getting It Right

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October 11, 2009:  South Korea has been told by the United States that the 177 JASSM missiles they had ordered (for use on their new F-15K aircraft, to take out North Korean air defenses) would not be available until sometime next year. South Korea had originally expected to begin receiving the missiles last year. But JASSM has been delayed due to test failures. However, the latest round of tests were over 90 percent successful. That kind of good news has arrived just in time.

For the last two years, the U.S. Department of Defense has been on the verge of cancelling the $6 billion JASSM cruise missile program. Lobbying, pleading, a large order from South Korea, and the growing possibility that the missile would be used against Iranian, Chinese or North Korean air defense systems, gave the program a few more lives.

The only problem JASSM has was that, well, it often didn't work. Until this year, the tests have been mostly failures. But the manufacturer has been able to identify all the problems in the failed tests, and convinced the government that these were the result of poor manufacturing. This problem, the builder promised, was fixed. As a result of this, sixteen more missiles, taken from those manufactured as part of the first order, were recently tested. If most, or even a large minority, of them had failed, JASSM would have been dead.

JASSM is the third family of GPS guided smart bombs to be developed. The original JDAM bomb kit (added to 500, 1,000 and 2,000 pound bombs), cost $26,000 each. The longer range JSOW (JDAM with wings and more powerful guidance system), cost $460,000 each. The even longer range JASSM cost $500,000 (the 400 kilometers version) to $930,000 (the 900 kilometer JASSM ER) each. Then there is the SDB (Small Diameter Bomb), a 250 pound JDAM that can also punch through concrete bunkers and other structures. These cost $75,000 each.

   The AGM-158 JASSM missiles are 2,300 pound weapons that are basically 1,000 pound JDAMS (GPS guided bombs) with a motor and GPS guidance kit added. JASSM was designed to go after enemy air defense systems, or targets deep in heavily defended (against air attack) enemy territory. The air force and navy planed to buy over 5,000 JASSM, but there has been opposition in the military and in Congress. The missiles are ten times more expensive than a JADM bomb of the same weight. But the aviators make the argument that many aircraft and pilots would be lost if the air defenses of a nation like, perhaps China, were attacked without using JASSM.

The U.S. Air Force ordered the AGM-158 JASSM into full production in early 2004. But only a few have been produced, because of test failures. Air force purchasing plans have been cut way back because of the reliability problems, and this has delayed shipment of the missiles to combat units until sometime next year.

JASSM is stealthy and uses GPS and terminal (infrared) guidance to zero in on heavily defended targets (like air defense sites.) The terminal guidance enables the missile to land within ten feet (three meters) of the aiming point. If there were a war with North Korea, for example, JASSM would be essential to taking out enemy air defenses, or any other targets that have to be hit early in a war (before air defenses can be shut down.) This capability is apparently what attracted the South Koreans, who now have F-15K aircraft that can carry JASSM.

JASSM was designed to handle the most modern Russian surface to air missiles, which are being sold to China. North Korea has older stuff, and can't afford the newer Russian SAMs. But even these older air defenses can be dangerous, and are best addressed with long range missiles. So there is a need for a missile like JASSM, one that works.