June 17, 2011:
The Norwegian firm Kongsberg has been successful in developing a "Joint Strike Missile" (JSM). What makes this missile special is that it is stealthy and designed to be launched from the internal bomb bay of the F-35 fighter. The half ton weapon, with a 250 kilometer range, is based on the existing Kongsberg NSM (Naval Strike Missile). Adapting this weapon for air launch got U.S. firm Lockheed Martin, and the U.S. Department of Defense, involved. JSM uses the NSM guidance system to hit moving targets, like ships. The JSM thus becomes a very useful weapon for nations adopting the F-35. The JSM is also superior to the heavier Harpoon, which has become a standard anti-ship missile in many navies. The JSM has other competition, like the Harpoon variant, SLAM-ER, but at the moment no one weapon has a lock on future anti-ship missiles.
JSM is based on the older, and quite successful, NSM. This is 410 kg (900 pound) missile is designed for use from ships or land based launchers (or trucks). NSM has a 125 kg (275 pound) warhead and a range of 185 kilometers. NSM uses GPS and inertial guidance systems, as well as heat imaging system (and a database of likely targets) for picking out and hitting the intended target. NSM entered service four years ago, and work on an air launched version led to the JSM. If JSM's advanced electronics (especially the gear that defeats defensive jammers) survives realistic testing, the new missile should be ready for service a year or so before the F-35 arrives in about 5 years.