Extremely Loaded Grain (HLG) Strong Rocket Motors permit prolonged vary and customised thrust profiles with the identical propellant and the identical measurement rocket motor.
Anduril and Raytheon introduced on Oct. 7, 2025 they carried out a static fireplace check of the previous’s Strong Rocket Motor (SRM) that includes a Extremely Loaded Grain (HLG) configuration. Anduril described the check as a “main development in propulsion expertise for air-to-air weapons,” which comes amid each a broad push in propulsion programs for missiles, and the event of long-range missiles themselves to match those fielded by Russia and China.
Whereas Anduril designed and developed the HLG-configuration motor utilizing expertise from Naval Air Weapons Station China Lake, Raytheon’s Superior Expertise Staff “supplied essential technical experience and oversight all through the event, design and execution phases of the check.” Neither firm specified when the check occurred.
This implies Raytheon certifying the dimensions and dimensions of the HLG SRM, beside setting the anticipated efficiency standards like burn charge and thrust wanted for air-to-air missiles. Each firms have been additionally underneath contract with the Air Pressure Analysis Laboratory Munitions Directorate.
Notably, Raytheon, a part of RTX, is the developer and producer of AIM-9 Sidewinder and AIM-120 AMRAAM sequence of missiles.
The HLG design was developed and constructed by Anduril utilizing expertise from Naval Air Weapons Station China Lake. The design allows considerably better volumes of energetic propellant, delivering elevated particular impulse and enhanced motor efficiency. These enhancements…
— Anduril Industries (@anduriltech) October 7, 2025
JATM, energetics and propulsion programs analysis
Lockheed Martin has been growing the AIM-260 JATM (Joint Superior Tactical Missile), whose renderings to this point have urged it isn’t an air-breathing system. HLG propellant expertise falls inside the ‘energetics’ space, which permits prolonged vary and customised thrust profiles with the identical propellant and the identical measurement rocket motor.
GE Aerospace additionally lately shed extra gentle on its hypersonic propulsion packages, with the testing of a Strong Gasoline Ramjet (SFRJ) and a dual-mode rotation-detonation combustion ramjet (DMRJ). On Might 6, Colorado-based Ursa Main additionally introduced a number of static fires assessments of a 5 inch stable rocket motor in a HLG configuration.
The U.S. was discovered to have lagged in energetics starting within the Nineteen Nineties, with China having surged forward, owing to each a drop in a R&D expenditure and the Pentagon’s efforts to extend the accuracy of weapons, reasonably than their vary or explosive drive.
The Energetics Expertise Middle (ETC), a nonprofit analysis group that does work for the federal government, touched upon the problem in a now eliminated 2021 Pentagon-commissioned report. “This can be a case the place we might probably be overwhelmed over the top with our personal expertise,” Bob Kavetsky, head of the Energetic Expertise Middle, instructed Forbes in Mar. 2023.
The check
Anduril mentioned that the design examined “allows considerably better volumes of energetic propellant, delivering elevated particular impulse and enhanced motor efficiency,” additional including “these enhancements translate instantly into prolonged vary and better tactical benefit.” This additionally follows Anduril commissioning its full-scale $75 million SRM manufacturing facility in Mississippi that affords “the much-needed scale, resiliency, and innovation to allied SRM manufacturing.”
— Anduril Industries (@anduriltech) August 5, 2025
Raytheon, in the meantime, mentioned that the check was part of a broader “response to the growing world demand for munitions,” for which the corporate has been “working with home and worldwide companions to reinforce U.S.-based rocket motor manufacturing capability.”
Anduril Industries’ senior vp Lt. Gen. Neil Thurgood referred to as designing and firing a Extremely Loaded Grain rocket motor “some of the technically demanding duties within the stable rocket motor business.” The check demonstrates Anduril’s “potential to ship high-performance propulsion options in a website lengthy outlined by a small set of suppliers.”
Missile propulsion and Past Visible-Vary Warfare
We’re assuming the JATM goes to be a non-air-breathing engine, in contrast to the Meteor BVRAAM, primarily based on renditions revealed on air drive funds paperwork, which didn’t present air intakes. There isn’t a data but on the missile’s seeker, navigation, steering and propulsion configuration.
A working data of missile expertise fitted to beyond-visual ranges of over 300 km, particularly with versatile kill chains that may additionally preserve the launching plane protected, tells us that the munition should have an energetic radar seeker programmed to activate in its terminal stage. Within the post-launch and cruise part, the missile should be able to receiving mid-course steering knowledge from both the launching jet or an exterior supply like an AEW&C plane by means of a two-way knowledge hyperlink.
Exterior steering retains the provider jet protected by permitting it to maintain its radar turned off in a heavy digital warfare jamming setting. An AEW&C plane is even safer, working farther away from the core battlespace. As for the propulsion system, a dual-pulse rocket motor that may fireplace a second time throughout its descent in direction of the goal, following the preliminary climb after launch, maintains the missile’s pace, velocity, kinetic power and thereby permits a shorter journey time to the goal.
Medium and long-range missiles, just like the AIM-120 AMRAAM, have been identified to make the most of this ‘lofting’ method to enhance their vary. Upon launch, it climbs up in a parabolic arc into rarified air at excessive altitudes. The shortage of air resistance and little drag permits better kinetic power, and a wider goal scan space with an energetic seeker when it begins descending.
