Aurora Resistojet Module (ARM)
Small thruster modules that run on a water-based propellant, used to steady, turn and move CubeSats and small satellites up to about 300 kg.
Why it matters
Water is cheap, safe to handle and needs no pressurized tank, so small satellites can get propulsion without hazardous-materials handling at the launch site.
How the technology works
A resistojet heats propellant with an electric element and expels the vapor through a nozzle. ARM thrusters weigh about a gram and are designed for water, though they can use other propellants.
ARM first flew on AuroraSat-1 in 2022 as a six-thruster attitude control unit; four ARM-C thrusters flew on C3S's Wisdom satellite in November 2025.
Sources
Updated Oct 22, 2026 · How we source facts · Suggest a correction