Naval Surface Warfare Center Indian Head Division has finished mixing the last batch of propellant for a program to refill Mk 104 rocket motors, which power the Navy’s Standard Missiles. The Navy calls it a key step in ramping up production of the motors.
The final batch was mixed for the Mk 104 Dual Thrust Rocket Motor sustainment program, the command announced on its Facebook page. The goal is to scale up propellant production so Indian Head can regrain Mk 104 motors, meaning it refills existing motor cases with new solid propellant.
The work supports the Surface Ship Weapons program under the Navy’s new Portfolio Acquisition Executive for Munitions, established in May to speed up the development, production and delivery of Navy weapons.
Testing comes next
Indian Head technicians will test samples from the final batch, along with small-scale motors cast from it, to check the propellant’s chemical makeup and performance.
The Navy is doing the work with defense contractor L3Harris. The aim is to build manufacturing capacity that can be scaled up quickly to meet wartime demand.
A key motor for the fleet
The Mk 104 is a solid rocket motor used across the Standard Missile family, which Navy ships use for air defense, surface warfare and ballistic missile defense. According to L3Harris, the Mk 104 is the second stage on the SM-3 and SM-6 missiles and the only stage on the SM-2.
Supplying enough of those motors has been one of the hardest parts of missile production. SM-6 missiles have taken 36 months or more to build, largely because of limited solid rocket motor supply. Meanwhile, the Navy’s fiscal 2027 budget request seeks 540 SM-6s, up from 166 funded this year.
Part of a bigger push at Indian Head
The Mk 104 milestone is the latest in a series of steps Indian Head has taken to boost the country’s rocket motor supply.
In January 2024, the command signed a 10-year public-private partnership with Aerojet Rocketdyne, now part of L3Harris, to increase solid rocket motor production. The agreement uses Indian Head’s designation as a Center for Industrial and Technical Excellence.
This summer, Indian Head cast its first regrained Mk 70 solid rocket motor in June, refilling a salvaged booster case with about 1,500 pounds of propellant. In August it successfully test-fired the motor, the largest cast composite solid rocket motor the command has ever tested. The Navy said that work makes Indian Head the Defense Department’s second source for reclaimed and regrained solid rocket motors.
“Today’s successful demonstration is a major win for the Arsenal of Freedom,” Capt. Paul Mahoney, Indian Head’s commanding officer, said after the August test.
Indian Head, on the Potomac River in western Charles County, has been part of the Navy since 1890. It is a Naval Sea Systems Command field activity and serves as the Navy’s lead center for ordnance, energetics and explosive ordnance disposal.
