Orbital HEXFlow — Water Ice Expansion Hydraulics for Intermittent Spacecraft Actuation

This conceptual white paper describes a proposed spacecraft mechanism that uses the expansion of freezing water to displace hydraulic fluid and produce a short mechanical stroke. The stroke could operate a latch or release mechanism directly, or charge an accumulator for later use. The paper compares a stationary cartridge with switched thermal links and a rotating ring that moves cartridges through warm and cold sectors. It presents screening calculations for a reference latch duty and outlines a proposed test programme. No prototype or flight-test results are reported.