The U.S. Navy recently received the first production version of the new Standard Missile 6 (SM-6) anti-aircraft missile. This new missile basically takes the existing SM-2 anti-aircraft missile and adds the more capable guidance system of the AMRAAM air-to-air missile. The SM-6 is a 1.5 ton, 6.55 meter (21.5 foot) long, 533mm (21 inch) diameter missile. It has a max range of 240 kilometers and max altitude of 33 kilometers (110,000 feet).
The older SM-2 is 1.35 ton, 8 meter (26.2 foot) long missile with a max range of 190 kilometers and max altitude of 24.4 kilometers (80,200 feet). The main change is the AMRAAM guidance system, which is self contained, and will seek out any target it comes within range of. The SM-2 uses a "semi-active" guidance system which requires that a special targeting radar "light up" the target with a radar beam, which the SM-2 guidance system detects and homes in on. The "active" guidance system of the SM-6 is thus harder to jam and can home in on targets beyond the range of targeting radars.
The SM-6 took seven years to develop and get into production and will replace many of the SM-2 missiles currently carried by American and Australian warships.