en.Wedoany.com Reported - Rubicon Space Systems has completed hot-fire testing of its Velox 5-Newton ASCENT monopropellant thruster, paving the way for on-orbit operations in 2027.

The tests were conducted in Rubicon's vacuum altitude simulation chamber in Huntsville, Alabama, using ASCENT propellant. ASCENT, which stands for Advanced Spacecraft Energetic Non-Toxic Propellant, is a hydrazine replacement fuel.

Daniel Cavender, director at Rubicon, told SpaceNews that the program exceeded design targets. The weeks-long hot-fire test campaign covered the full feed pressure range from 25% to 125% of rated pressure and mapped the full duty cycle range from 1% to 100%. He added that the team now understands where the thruster's performance margins lie, where behavioral changes occur, and what changes can be expected with accumulated life.

The hot-fire tests verified the thruster can handle a throughput of nearly 14 kilograms of propellant. According to public reports, this is the largest throughput demonstrated among 5-Newton or 1-Newton class ASCENT monopropellant thrusters. Cavender said that every additional kilogram of propellant the thruster processes translates into greater mission capability and flexibility. ASCENT is nearly 50% denser than hydrazine, and the specific impulse measured during testing was 255 seconds, nearly 10% higher than hydrazine thrusters.

Following the tests, Rubicon has transitioned the thruster to flight production for three undisclosed customers. The first customer delivery is scheduled for early 2027 for a mission in late 2027, with another mission set for 2028.

ASCENT was developed by the U.S. Air Force Research Laboratory in the 1990s. Cavender previously worked on ASCENT-related missions during his tenure at NASA. He stated that the combination of high throughput and high performance will enable mission capabilities beyond what current state-of-the-art hydrazine thrusters can achieve. Rubicon received a NASA contract in 2025 to develop a 110-Newton ASCENT thruster prototype. The company has also delivered the propulsion system for NASA's Green Propulsion Dual Mode technology demonstration mission, which is scheduled to launch later this year. Rubicon, founded in 2022, is a division of Plasma Processes.