Phase Four

Phase Four is a leading provider of electric propulsion systems for small satellites, developing innovative radio-frequency thrusters that simplify spacecraft propulsion while reducing size, weight, and cost. The Hawthorne, California company produces turn-key plasma propulsion systems for commercial and government customers.

In July 2024, Phase Four announced the Maxwell Block 3 plasma propulsion thruster, with orders open for Q1 2024 delivery from the company's new 25,000 square-foot manufacturing facility. Maxwell Block 3 offers significantly shorter lead times and lower prices compared to legacy plasma propulsion systems while exceeding Hall effect thruster performance.

In October 2024, Phase Four announced commercialization of monopropellant multi-mode capability, combining high-thrust chemical propulsion with efficient electric propulsion using a single propellant. The RF thruster uniquely supports chemical propellant integration, eliminating auxiliary xenon or krypton tanks required by other multi-mode systems. Ground demonstrations using ASCENT and hydrazine systems are planned with DoD and private partners by Q1 2025.

The hallmark of Phase Four's technology is flexible architecture utilizing traditional noble gases and alternative propellants including iodine, water, and air. The next-generation RF plasma thruster doubles peak specific impulse above 900 seconds compared to earlier blocks, doubling total impulse for fixed propellant tank sizes. Phase Four continues advancing versatile electric propulsion technology for the growing small satellite market.