Phase Four Wins USAF to Adapt Maxwell In-space Engine for Defense Needs

EL SEGUNDO, Calif., March 17, 2020 (Phase Four PR) — Phase Four, makers of radio frequency (RF) plasma engines for in-space propulsion, has been awarded an SBIR Phase I contract by Air Force tech accelerator AFWERX, in partnership with the Air Force Research Laboratory and the National Security Innovation Network.

As part of this partnership, beginning in March 2020, Phase Four will work with the Air Force to adapt its revolutionary Maxwell in-space propulsion system to meet the needs of defense users.

Affordable and reliable in-space propulsion is an essential requirement for both commercial and defense next-generation satellite constellations. The Phase Four radio-frequency thruster (RFT) is the first solution to address the cost, manufacturing, and performance needs of high volume satellite constellations. Its simple architecture allows manufacturing to scale up easily, and accommodates a wide range of solid, liquid, and gas propellants. In turn, these features potentially open an even wider range of mission possibilities, including missions in deep space and very low Earth orbit.

Maxwell is a complete in-space propulsion system built on Phase Four’s RFT. It includes power electronics, software, and a pressurized storage vessel for 1 kg of xenon, providing over 10,000 Ns of impulse. Maxwell is delivered in an enclosure smaller than 19 cm x 19 cm x 14 cm. Customer deliveries began earlier this month.

“We’re proud to be selected by the Air Force as one of its potential technology partners. This is a great example of how Phase Four’s commercial success with Maxwell in the private sector can translate to defense needs,” said Beau Jarvis, CEO.

“With space now a contested domain, we look forward to collaborating with the Air Force to provide United States space assets with the superior maneuverability and resiliency required to ensure mission success,” added Jason Wallace, Vice President of Advanced Development.

About Phase Four

Phase Four is a disruptive provider of simple electric propulsion (EP) solutions for small satellites. The company was founded in 2015 to address the demands of next generation 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. Learn more at


AFWERX serves as an entry point for industry to do business with the Air Force, with the mission of making the Air Force more innovative by uncovering ideas and opportunities to improve the service, connecting ideas with legitimate solutions, and transitioning tools to the warfighter.

AFWERX, in partnership with the Air Force Research Laboratory and National Security Innovation Network, developed the Small Business Innovation Research (SBIR) “Open Topics,” to increase the efficiency, effectiveness, and transition rate of the existing SBIR program. SBIR enables the Air Force to develop and adopt commercially viable innovations as integrated program components or operationally effective commercial off-the-shelf solutions. Learn more at