Phase Four and Impulse Space to Collaborate on Multi-Mode Propulsion

Multi-Mode propulsion enables new mission capabilities
 for the commercial in-space mobility market

EL SEGUNDO, Calif., June 8, 2022 /PRNewswire/ -- 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. The companies seek to explore and collaborate on opportunities to develop and market multi-mode propulsion capabilities that may be employed by future commercial space vehicles. The companies will evaluate the performance of Phase Four's propellant-agnostic RF Thruster on green propellants of interest.

"Multi-mode propulsion systems are compelling because they allow a space vehicle to have two vastly different thrust and efficiency operating points, but leverage a single propellant supply, saving mass and cost," said Phase Four CEO, Beau Jarvis. "We are excited to work with the Impulse Space team to bring this novel propulsion capability to market and support the Impulse mission of developing vehicles that are capable of delivering multiple payloads to unique orbits from a single launch."

Phase Four's Maxwell Block 1 engine gained flight heritage in 2021 and is currently operating on several commercial small satellites. The company has begun production of its Block 2 Maxwell engine. Block 2 utilizes the company's second generation RF Thruster and offers significant performance improvement over the Block 1 engine. Phase Four is also working to adapt its RF Thruster to operate on nontraditional propellants that are less expensive and more readily obtained than purified noble gasses like xenon and krypton. The company recently won a Space Force Pitch Day award to test on green propellant.

"The space vehicles in development by Impulse Space address missions for all orbits and will benefit considerably by having the added capability of the Phase Four's Maxwell engine," said Tom Mueller, CEO of Impulse Space. "As we focus on offering the broadest breadth of missions for our customers, we are eager to extend the efficiency of propulsion systems to include Phase Four's products, ultimately enhancing those missions."

Phase Four will perform exploratory performance testing with its RF Thruster operating on propellants of interest to Impulse Space. The cooperative effort may also include an in-space multi-mode capability demonstration with an Impulse Space vehicle.

About Phase Four

 Phase Four is a disruptive provider of next generation electric propulsion (EP) solutions for small satellites. The company was founded in 2015 to address the demands of the rapid proliferation of satellite constellations and to accelerate the advancement of its radio-frequency thruster (RFT). The Phase Four RFT 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 small satellite operators. Learn more at

About Impulse Space Propulsion

Founded in 2021, Impulse Space Propulsion is a Space 2.0 pioneer providing agile, economical last-mile space payload delivery capabilities. With a near-term focus on Low Earth Orbit (LEO), services include in-space transportation, orbital transport of satellites to optimal orbits, in-orbit servicing, space debris deorbit and space station orbit keeping. Long-term, Impulse will include focus on Geostationary Earth Orbit (GEO), lunar and beyond, to provide transport of space resources, lunar missions including landers, planetary missions, asteroid resources, in-space manufacturing and propellant depots.

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SOURCE Phase Four