Building the Next Generation of

In-Space Mobility


Maxwell Systems Delivered


Maxwell systems on-orbit today


Systems produced by Q2 2022



Phase Four is a disruptive provider of next generation electric propulsion (EP) solutions for small satellites. Phase Four’s RF Thruster represents a revolutionary new architecture that realizes lower cost, mass-manufacturability, miniaturized power electronics, and propellant agnosticism over incumbent technologies, without compromising performance. In 2021 Phase Four’s Maxwell turn-key propulsion system achieved flight heritage and is now being regularly utilized by satellite operators.


Maxwell Engine Blocks and Rocket


At Phase Four we are constantly pushing the envelope of RF plasma propulsion. We have active R&D in plasma physics of RF thrusters, advanced propellants, and new applications of plasma propulsion in space.


Maxwell is a high performance turn-key plasma propulsion system that leverages miniaturized RF electronics and our electrodeless thruster in a compact form factor.

PlasmaWorks and Maxwell in Space


Read more about us and updates in the news.

A Maxwell Block 2 engine undergoing environmental testing at Phase Four
Jim Bridenstine, Former NASA Administrator, joins Phase Four’s Board of Directors
Bridenstine brings a wealth of industry experience and a commitment to space sustainability
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Jim Bridenstine
Former NASA administrator joins board of spacecraft propulsion startup Phase Four
Former NASA Administrator Jim Bridenstine joined the board of directors of spacecraft propulsion startup Phase Four, the company told CNBC.
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Phase Four's RF Thruster operating on a nitrogen-oxygen blend
Phase Four and Impulse Space to Collaborate on Multi-Mode Propulsion
Phase Four, the creator of the radio-frequency thruster (RF Thruster) for satellite propulsion, announced today that it has signed a memorandum of understanding with Impulse Space, a Space 2.0 pioneer providing agile, economical last-mile space payload delivery capabilities.
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