Rubicon wins NASA and AFRL ASCENT thruster contracts

SAN FRANCISCO — Rubicon Space Systems won a series of contracts with a combined value of about $6 million to deliver ASCENT thrusters to NASA and the Air Force Research Laboratory in 2024.

“Collectively, these three awards represent NASA and AFRL’s immense interest and trust in Rubicon as a champion of ASCENT-based propulsion,” Daniel Cavender, Director of Rubicon, a division of Plasma Processes, told SpaceNews. “This also represents both organizations’ keen interest in advancing ASCENT.”

ASCENT is a non-toxic propellant developed by the Air Force Research Laboratory.

The “Holy Grail”

Under a $5.1 million AFRL award, Alabama-based Rubicon will manufacture 10 one-newton thrusters and qualify the thrusters for spaceflight.

In addition, NASA Marshall Space Flight Center awarded Rubicon a $630,000 contract to develop the chemical component of a dual-mode propulsion system for a NASA mission. Both the chemical and electric thrusters in the dual-mode system would draw ASCENT from a single tank.

Dual-mode propulsion systems offer “the high-thrust benefit of the chemical side but also the high efficiency of the electric propulsion elements,” Cavender said. “People colloquially refer to dual-mode as the holy grail of propulsion.”

Rubicon also is developing a 110-newton ASCENT thruster for NASA Marshall, under a $280,000 Small Business Innovation Research Phase 3 award. That development campaign is important because 110 newtons is the “highest thrust class ASCENT-based thruster ordered to date,” Cavender said.

Gaining Steam

AFRL began developing ASCENT in the 1990s. The propellant was first flight tested on NASA’s Green Propellant Infusion Mission in 2019. Cavender, who was closely involved with that program as well as the ASCENT-fueled Lunar Flashlight, said ASCENT offers “performance and safety” that exceeds that of “hydrazine-based propulsion offerings.

Still, determining the appropriate propellant for each mission remains “up to the user,” Cavender said. “What’s important to them?”