The SM-2 replaced SM-1 and added a programmable auto-pilot so that it could be command-guided into a homing "basket" near the projected position of the target. SM-2 was the first tactical missile to incorporate inertial navigation to guide the missile from launching ship up to the homing "basket." These missiles are also part of the New Threat Upgrade (NTU) to existing missile systems.
As these missiles do not have to "ride" a illuminated beam all the way to the target, they can fly more a more fuel-efficient route thus greatly improving their effective range.
The SM-1 MR, SM-2 MR, SM-3 MR and Tartar missiles are virtually identical in appearance but quite different in performance.
| Designation | SM-2 MR RIM-66C, RIM-156 |
|---|---|
| Ship Class Used On | Many |
| Date In Service | 1981 |
| Weight | 1,380 lbs. (621 kg) |
| Dimensions | Body: 13.5 x 175 in (34 x 445 cm) Wing span: 61.8 in (157 cm) |
| Payload | 250 lbs. (113 kg) continuous rod |
| Range | 3,000 - 180,000 yards (2,750 - 165,000 m) |
| Propulsion | Boost-sustainer rocket |