In order to keep its pilots out of enemy cross-hairs but still be able to deliver devastating strikes against hardened bunkers, the USAF has spent the better part of two decades developing a family of long-range, semi-autonomous cruise missiles called the Joint Air-to-Surface Standoff Missile. And the latest JASSM progeny now can hit targets more than twice as far as its predecessors.
These stealth subsonic cruise missiles measure 4m long with a Teledyne turbojet engine, and are shaped to minimise their radar cross sections. Each is packed with a 450kg conventional warhead and can be carried by a variety of US aircraft including the B-2A Spirit stealth bomber, B-1B Lancer, B-52H Stratofortress, F-15E Strike Eagle and F-16 Falcon. The missile's onboard GPS provides navigation from launch until its final approach of the target, up to 370km away, whereupon its infrared seeker takes over.
The US Air Force began developing the AGM-158 JASSM line back in 1995, though the program has been beset by a number of near-cancellations since then due to performance and design issues. However, the Air Force has used the lessons learned from these setbacks to steadily improve the JASSM line, culminating in the newest iteration: the JASSM-ER (extended range).
The JASSM-ER can travel 925km to its target — more than 2.5 times farther than the JASSM — thanks to a larger fuel tank and more efficient turbofan engine. Plus, it has been electronically hardened to withstand GPS jamming signals. Other improvements, including a submunition dispenser, had been considered but were ultimately left out of the ER design. Still, the two variants share more than 70 per cent of the same hardware, which helps reduce production costs.
The JASSM-ER officially entered service in April of this year and was approved for full-rate production earlier this month. In all, the USAF reportedly plans to purchase 2400 of the $US700,000 JASSMs and nearly 3000 of the ER variants, each costing around $US1.32 million apiece, throughout the missile line's production cycle — which is expected to last throughout the 2020s. By then, presumably, the USAF will have developed an even more efficient means of blowing buildings up from the other side of the horizon. [Wiki - Lockheed - DID - Missile Threat]