The PBR-50 (Water Resistojet Thruster) is a high-performance water vapor propulsion system designed in a Φ250 × 300 mm form factor, delivering high thrust and total impulse optimized for 100–200 kg microsatellites. The system is fully integrated, incorporating the thruster head, fluidics, electronics, and propellant tank within a single unit. Its clusterable architecture also enables scalability across a wide range of spacecraft sizes and mission profiles.

The PBR-50 uses water as propellant, eliminating the need for high-pressure storage systems. The propellant is preloaded into the tank prior to factory delivery, allowing satellite integrators to avoid complex fueling operations during spacecraft integration.

The propulsion system was first launched in 2024 and successfully completed its mission. An additional batch of flight units was integrated by Axelspace in May and is currently waiting for launch.