The early SM-3 TSRM was made by Thiokol and later ATK. The motor weighs 250 lbs, of which 195 is the dual-pulse multi-grain TP-H-3340A-based propellant.

A SM-3 Block I ignites its Third Stage Rocket Motor (TSRM). After coasting to an altitude of 56 km and above speed of Mach 6. The TSRM gives the SM-3 Kinetic Warhead (KW) the necessary kick to continue its journey towards space.

Forgot to mention, but the MK.72 is the first stage rocket motor of all these missiles.

The rocket motor uses 4 electro-mechanical actuated nozzles made by Parker-Bertea. The nozzles can be deflected +14.5°. The TVC mechanism is a ball and socket. It was made by the Chemical Systems Division of United Technologies.

The Mk.72 rocket motor weighs in at 1,500 lbs. It uses an all-boost HTPB-AP propellant grain. It makes up roughly half the weight of each SM. The booster has a burn time of 6 seconds and remains the largest MK.41 VLS-launched booster.

A Standard Missile 2 Block IV pulls a hard maneuver out of a land-based VLS. The SM-2 Block IV, IVA, SM-3 Block I, IA, IB, IIA, and the SM-6 Block I, IA, and IB all use the same Mk.72 rocket motor.

Onboard footage from inside the nose cone was recorded by an Instrumented SM-3 KW.

The clam shell removes this unnecessary maneuvering of the TSRM (Third Stage Rocket Motor) and allpws the KW to see the target immediately after the nose cone opens up.

This test serves as early de-risking for the jointly developed SM-3 Block IIA variant. Prior Standard Missile variants (SM-3 I/IA/IB) have a nose cone that is ejected. The TSRM has to turn 30° from the direction of the target, eject it, and then face the target again.

SM-3 Block I missile tests a new clamshell nose cone designed by Japan during Joint Control Test Vehicle-1 (JCTV-1).