The Standard ERAM is a two-stage missile with a booster stage and a second stage.
It is similar in appearance to the RIM-156A Standard missile.
The radar seeker is an enlarged version adapted from the AIM-120C AMRAAM seeker (13.5 in (34 cm) versus 7 in (18 cm)).
The missile may be employed in a number of modes: inertial guided to target with terminal acquisition using active radar seeker, semi-active radar homing all the way, or an over the horizon shot with Cooperative Engagement Capability.
The missile is also capable of terminal ballistic missile defense as a supplement to the Standard Missile 3 (RIM-161).
Unlike other missiles of the Standard family, the Standard ERAM can be periodically tested and certified without removal from the vertical launching system.

The SM-6 offers extended range over previous SM-2 series missiles, primarily being able to intercept very high altitude or sea-skimming anti-ship missiles, and is also capable of performing terminal phase ballistic missile defense.
The SM-6 can also function as a high speed anti-ship missile.
It can discriminate targets using its dual-mode seeker, with the semi-active seeker relying on a ship-based illuminator to highlight the target, and the active seeker having the missile itself send out an electromagnetic signal; the active seeker has the ability to detect a land-based cruise missile amid ground features, even from behind a mountain.
The multi-mission SM-6 is engineered with the aerodynamics of an SM-2, the propulsion booster stack of the SM-3, and the front end configuration of the AMRAAM.
Estimates of the SM-6's range vary; its official published range is 130 nmi (150 mi; 240 km), but it could be anywhere from 200 nmi (230 mi; 370 km) to as much as 250 nmi (290 mi; 460 km).

The U.S. Navy is adding the GPS guidance to the SM-6 Block IA so that it has the capability to strike surface targets if needed, but given its higher cost than other land attack weapons like the Tomahawk cruise missile it would not likely be used as a primary option.
In February 2016, Secretary of Defense Ashton Carter confirmed that the SM-6 would be modified to act as an anti-ship weapon.

On January 17, 2018 the U.S. Navy approved plans to develop the SM-6 Block IB, which will feature a 21-inch rocket motor instead of the current 13.5 inch motor.
The new variant will significantly increase the missile's range and speed enabling a hypersonic and extended range anti-surface warfare capability.
The Standard ERAM is a two-stage missile with a booster stage and a second stage. It is similar in appearance to the RIM-156A Standard missile. The radar seeker is an enlarged version adapted from the AIM-120C AMRAAM seeker (13.5 in (34 cm) versus 7 in (18 cm)). The missile may be employed in a number of modes: inertial guided to target with terminal acquisition using active radar seeker, semi-active radar homing all the way, or an over the horizon shot with Cooperative Engagement Capability. The missile is also capable of terminal ballistic missile defense as a supplement to the Standard Missile 3 (RIM-161). Unlike other missiles of the Standard family, the Standard ERAM can be periodically tested and certified without removal from the vertical launching system.
The SM-6 offers extended range over previous SM-2 series missiles, primarily being able to intercept very high altitude or sea-skimming anti-ship missiles, and is also capable of performing terminal phase ballistic missile defense. The SM-6 can also function as a high speed anti-ship missile. It can discriminate targets using its dual-mode seeker, with the semi-active seeker relying on a ship-based illuminator to highlight the target, and the active seeker having the missile itself send out an electromagnetic signal; the active seeker has the ability to detect a land-based cruise missile amid ground features, even from behind a mountain. The multi-mission SM-6 is engineered with the aerodynamics of an SM-2, the propulsion booster stack of the SM-3, and the front end configuration of the AMRAAM. Estimates of the SM-6's range vary; its official published range is 130 nmi (150 mi; 240 km), but it could be anywhere from 200 nmi (230 mi; 370 km) to as much as 250 nmi (290 mi; 460 km).
The U.S. Navy is adding the GPS guidance to the SM-6 Block IA so that it has the capability to strike surface targets if needed, but given its higher cost than other land attack weapons like the Tomahawk cruise missile it would not likely be used as a primary option. In February 2016, Secretary of Defense Ashton Carter confirmed that the SM-6 would be modified to act as an anti-ship weapon.
On January 17, 2018 the U.S. Navy approved plans to develop the SM-6 Block IB, which will feature a 21-inch rocket motor instead of the current 13.5 inch motor. The new variant will significantly increase the missile's range and speed enabling a hypersonic and extended range anti-surface warfare capability.
RIM-174 Standard ERAM