The U.S. Navy has moved to strengthen its missile defense and strike capabilities by awarding Northrop Grumman a $94.3 million contract to develop a new 21-inch diameter second-stage rocket motor. The propulsion upgrade is aimed at expanding the reach and effectiveness of the SM-6 missile family against advanced air, surface, and hypersonic threats, signaling a focus on rapid performance gains within existing weapon systems.
According to Northrop Grumman, the contract covers continued design and qualification work along with the initial production of 60 solid rocket motors. All manufacturing and testing will take place at the company’s Propulsion Innovation Center in Maryland, supporting a comprehensive qualification program that includes static firings, environmental stress testing, and early flight integration. The scope of the effort suggests the Navy is preparing the motor for operational deployment rather than experimental use.
The technical advantage of the new motor lies in its full 21-inch diameter, which provides significantly more internal volume than the sustainers used on current SM-6 configurations. This additional space allows for increased propellant mass, improved insulation, and optimized thrust profiles, delivering greater total impulse and sustained speed throughout the missile’s flight. These characteristics are particularly important for engaging maneuvering targets that demand high closing energy in the terminal phase.
The propulsion upgrade aligns closely with the Navy’s plans for the SM-6 Block IB, an extended-range variant designed to expand both defensive and offensive reach without altering compatibility with the Mk 41 Vertical Launch System. By fielding a full-diameter second stage, the Navy can push the missile’s kinematic envelope while preserving commonality with existing launch infrastructure. The contract underscores a broader strategy to counter emerging hypersonic and long-range threats through incremental but impactful enhancements to proven missile systems.
