DARPA Awards Phase Four $14.9M For Low Earth Orbit Electric Propulsion

Phase Four, a provider of electric propulsion (EP) solutions for satellites, has secured a substantial $14.9M contract from the Defense Advanced Research Projects Agency (DARPA).

The contract aims to support the development of an “air-breathing” EP system tailored for Very Low Earth Orbit (VLEO) operations, encompassing altitudes as low as 90-450km.

Phase Four's radio-frequency thruster under test at its facility in Hawthorne, CA. Credits: Phase Four — *Phase Four’s radio-frequency thruster under test at its facility in Hawthorne, CA. Credits: Phase Four*

This significant award is part of DARPA’s Otter program, designed to pioneer, demonstrate, and gather on-orbit data for “air-breathing” electric propulsion technologies. These advancements will tap into ambient low-density air as propellant, facilitating prolonged satellite operations within VLEO altitudes.

Notably, the culmination of the Otter program will feature a lengthy “orbiting wind tunnel” spaceflight demonstration, meticulously scrutinizing the performance of the “air-breathing” electric propulsion system within the orbital realm.

Technology tailored for VLEO

Leveraging Phase Four‘s radio frequency thruster (RFT) technology, the Otter program seeks to overcome the limitations of traditional electric propulsion systems, which often deteriorate when exposed to non-traditional propellants. The RFT’s propellant-agnostic nature uniquely positions it to operate efficiently using the low-density air harvested within the VLEO environment.

Building upon a prior collaboration with DARPA, which yielded a proof-of-concept thruster prototype for innovative, cost-effective propellants, the company is poised to drive significant advancements in in-space propulsion capabilities.

“Phase Four is honored to bolster DARPA’s initiatives aimed at propelling in-space propulsion capabilities forward,” said Umair Siddiqui, President, Chief Technology Officer, and Principal Investigator at Phase Four.

“Having designed and deployed electric propulsion systems aboard nine satellites, accumulating over 5,300 days of on-orbit flight heritage since our inception, we are excited to contribute our expertise, experience, and innovative ethos to the Otter program.”

An expanding company

Jason Wallace, President of Government Programs, emphasized the expansion of the company’s propulsion capabilities across the entire space domain, from near-space to deep space, with the inclusion of the Otter program.

“We look forward to working closely with DARPA to unlock sustained missions in VLEO, which will increasingly become a critical operational environment for national security as traditional orbits become congested and contested,” he added.

*Phase Four’s Maxwell propulsion solution. Credits: Phase Four*

The company, founded in 2015, offers electric propulsion solutions tailored for small satellites. Their RFT technology hopes to deliver cost-effective and reliable propulsion without compromising performance.

Moreover, in 2021, Phase Four’s Maxwell turn-key propulsion system achieved flight heritage and is now used among small satellite operators, further solidifying its position as a player in the space propulsion sector.