Benchmark Space Systems has developed and tested thrusters up to the 500 newton class. Credit: Benchmark Space Systems

SAN FRANCISCO – Benchmark Space Systems won a $2.81 million U.S. Air Force Research Laboratory contract to continue development and testing of thrusters running on Advanced Spacecraft Energetic Non-Toxic, ASCENT, fuel.

The two-year award announced Aug. 29 was Benchmark’s second AFRL SPRINT award. AFRL issued a Broad Agency Announcement in 2019 called Space Propulsion Research and Innovation for Neutralizing Satellite Threats, known as SPRINT, seeking proposals of interest to AFRL’s Space Propulsion Research Branch.

Under the new AFRL-funded program, Benchmark is building a 22 Newton thruster for ASCENT hot-fire demonstrations. In addition, Burlington, Vermont-based Benchmark will deliver a preliminary design of a 100 Newton thruster assembly in 2025.

Optimizing for Size, Weight and Longevity

With funding from its first SPRINT award, Benchmark developed and demonstrated a prototype thruster that burns ASCENT fuel without a catalyst. The prototype thruster was a proof of concept and was not optimized for spaceflight.

“In this phase, we’re designing a thruster that you can apply to an operational mission,” Jake Teufert, Benchmark chief technology officer, told SpaceNews. “Now, weight matters and longevity matters.”

ASCENT Through the Years

ASCENT was first launched in 2019 on NASA’s Green Propellant Infusion Mission. NASA’s Lunar Flashlight, a cubesat launched in 2022 to observe water ice deposits on the moon, was also powered by ASCENT.

“Years of work have been put into operationalizing ASCENT, a high-performance, storable monopropellant that has the opportunity to increase mission capability beyond what’s offered by hydrazine,” Teufert said. “With this contract, we’re taking ASCENT from lower-thrust demonstrators and scaling that up to where it’s addressable for every mission that the DoD currently performs” with hydrazine.

Advanced Propellants Group

Benchmark also is establishing an Advanced Propellants Group led by Michael Martin, a mechanical engineer with a PhD from Texas A&M University, to test a variety of nontoxic chemical, electric and hybrid propulsion systems.

The new organization will “look at all these new monopropellants that are coming out and other bipropellants and develop both thrusters that can utilize them but also ways to modify existing propellants,” Martin said. “For instance, this thruster that we’re developing for AFRL has a potential to be used with other monopropellants that are currently available in Europe and Japan. You could end up having families of thrusters using the different monopropellants.”

U.S. International Traffic in Arms Regulations (ITAR) prevent the export of ASCENT. The ability to use different propellants could pave the way to foreign sales of new Benchmark thrusters.

Benchmark employs “non-toxic propulsion professionals who will open the door even wider for ASCENT usage, as we also explore bringing in other underutilized and promising green chemical, electric and hybrid technologies to power the space economy,” Martin said in a statement.

Tactical Responsiveness

Martin, who has worked with ASCENT for more than three years, said, “what I really liked about it is that I can wear a lab coat and gloves to work with this propellant. It’s also easy to store and transport.”

In contrast working with hydrazine requires Self Contained Atmospheric Protection Ensemble or SCAPE suits.

Teufert added that ASCENT will be “particularly powerful and important” for responsive space applications, where satellites may be stored on the ground or in an orbital warehouse.

ASCENT “is a propellant you can load into the satellite that is sitting on a shelf ready to be integrated at a moment’s notice,” Teufert said. “You can’t do that with a hydrazine system.”

Debra Werner is a correspondent for SpaceNews based in San Francisco. Debra earned a bachelor’s degree in communications from the University of California, Berkeley, and a master’s degree in Journalism from Northwestern University. She...