The increase in diameter to a uniform 21 inches provides more room for rocket fuel, permitting the Block IIA version to have a burnout velocity (a maximum velocity, reached at the time the propulsion stack burns out) that is 45% to 60% greater than that of the Block IA and IB versions, (7) as well as a larger-diameter kinetic warhead.
We also will continue the co-development of the SM-3 IIA interceptor with the Government of Japan to increase significantly the area defended by the Aegis BMD system with its 21-inch diameter rocket motors, two-color seeker, and increased kinetic warhead divert capability.
SM-3 features a third stage rocket motor, GPS guidance and a kinetic warhead
to intercept and destroy short and medium-range ballistic missiles in space.
The improved SM-3 also has a Throttleable Divert and Attitude Control System which allows the kinetic warhead
to propel itself toward incoming threats using short bursts of precision propulsion.
The SM-3 LEAP's kinetic warhead
is designed to intercept an incoming theater ballistic missile outside the earth's atmosphere.
This combines the Standard Block IV airframe with satellite/inertial navigation and a third rocket stage (Asas: Advanced Solid Axial Stage) that boosts the 20-kilogram Terrier Leap kinetic warhead
The next step is to show that the kinetic warhead
can go do what it needs to do to kill the target," said Jim Gillespie, director of theater missile-defense development at Lockheed Martin.