Open Arsenal

The Key to Reusable Space.

PhaseLock is a Cryogenic Conditioning Loop (CCL) designed to make in-space refueling physically stable and repeatable. In orbit, cryogenic propellants behave unpredictably—boiling, stratifying, and forming vapor pockets that disrupt transfer. PhaseLock addresses this at the hardware level by conditioning propellant before and during transfer, ensuring it remains in a controlled, single-phase state. Instead of treating refueling as a simple fluid transfer, PhaseLock treats it as a thermodynamic process that must be actively managed.

At its core, PhaseLock circulates propellant through a closed-loop system that regulates temperature, pressure, and phase consistency. It performs controlled chill-down of transfer lines and components, eliminating thermal shock and preventing flash boiling when propellant begins to move. Integrated vapor management captures and recondenses gas, maintaining mass balance and preventing pressure instability. Precision microvalves, pumps, and distributed sensors work together to maintain equilibrium across the entire system, even in microgravity conditions where fluid behavior is far less predictable than on Earth.

PhaseLock is built with safety and redundancy as fundamental principles. It includes automated isolation mechanisms to contain leaks or pressure anomalies, along with redundant sensor pathways and failover control to prevent single-point failures. The system can dynamically reroute flow, adjust circulation patterns, or enter a safe-state mode if conditions move outside acceptable limits. These features ensure that even under unexpected conditions, propellant remains contained, stable, and controllable.

Beyond its standalone capabilities, PhaseLock is designed to integrate seamlessly with predictive software like ForwardState. While PhaseLock handles the physical conditioning of propellant, it provides the stable foundation required for higher-level control systems to operate effectively. Together, they enable autonomous, vapor-free transfer and lay the groundwork for scalable orbital refueling infrastructure—transforming refueling from a risky maneuver into a reliable, repeatable operation essential for reusable spaceflight.