The U.S. Department of Defense is spending $137 million to develop an air launched version of the Patriot PAC-3 anti-missile missile. The $3.3 million PAC 3 has a shorter range (about 20 kilometers) than the 70 kilometers for the PAC 2 anti-aircraft version. A PAC 2 missile weighs about a ton, a PAC 3 weighs about a third of that. The PAC-3 is 17 feet (5.2m) long and 25cm (10 inches) in diameter. At 700 pounds, it is smaller than some of the bombs usually carried by fighter bombers. The flight control software will be modified for launch from F-15 fighters, and attachments designed so the PAC-3, inside a canister, can be hung from the fuselage of the F-15, where a fuel tank usually is, and fired by the pilot.
Launched from the air, the PAC-3 would have a longer range, and be able to knock down ballistic missiles during their launch phase (before they left the atmosphere, turned, and plummeted back to their target below.) The air launched PAC-3 would also be useful against cruise missiles. The air launched PAC-3 should be ready for service within three years.