Anduril RMS eyes revolution in solid rocket fuel with Alitec propellant

Anduril is developing the Alitec solid rocket propellant to enhance tactical missile performance. Above, Anduril test-fires its Denali 18 inch hypersonic rocket booster at its McHenry, Mississippi, solid rocket motor facility in November 2024. (Anduril)

Anduril Rocket Motor Systems (RMS) is in the final stages of qualifying a new solid rocket propellant that will increase range, payload, and speed of a missile by up to 40%, according to an Anduril statement in June. This is the first major change to solid rocket propellant since the 1950s, when Atlantic Research Corporation engineers Keith Rumbel and Charles Henderson came up with the formulation of aluminium solid fuel and ammonium perchlorate (NH4ClO4) solid oxidiser, Brielle Terry, vice-president and general manager for Anduril RMS, told Janes on 9 December during a visit to the company's facility in McHenry, Mississippi.

The key element of this formula is the large amount of hydrogen and oxygen. Rubber is added to the mix to hold the fuel together, Terry said. This “creates three things. Two of them we really like for a rocket motor and one of them is a by-product. For a solid rocket motor to work, we want the most gas we can possibly get and most gas usually means light gas” and hydrogen is the lightest gas, she explained. “The best rocket motors are hydrogen gas generators. We are not burning hydrogen; we are just spewing hydrogen. It's optimised such that hydrogen's coming out, not as water, but as just hydrogen. All the oxygen is getting paired with the aluminium to create aluminium oxide, which is heat … I want the most amount of gases … at the highest temperature.”