Condensation with vapor flow is one part of the fluid loop in a pumped phase-change heat transfer system. Phase-change heat transfer systems are desirable and advantageous to use in spaceflight for many of the same reasons that they are advantageous to use on Earth: greater power capacity than a single-phase pumped fluid loop, lower system volume compared to a single-phase pumped fluid loop, and superior uniformity of temperature on the heat transfer surface compared to a single-phase pumped fluid loop Pumped phase change loops also provide much greater power capacity than heat pipes do in spaceflight. The proposed flight test addresses a technology with has long been known to be of value to spaceflight systems and exploration but has yet to become common in use. Proposed is a sub-orbital flight test focused on verifying predictive technology for the control of droplets and avoidance of liquid plugs in tubes with and without flow as in a condenser of a zero-gravity pumped phase-change loop for use in spaceflight. Predictive capability for the shape and stability of droplets or plugs of liquid is important for details of condenser flow passage design. The proposed sub-orbital payload seeks to produce rapidly a proof to create confidence in a predictive tool yet, in the event of a negative outcome, it will serve as justification for necessary improved tool development. The payload flew twice on parabolic flights as a human-operated experiment and proved that such flights are too jittery for the testing. Thus, the newly available commercial sub-orbital flight is ideal for this topic. The payload will be rebuilt as an automated payload with multiple condensation tubes with controlled air flow and liquid injection (much better control of liquid position and volume than with condensation) to fit the single height standard payload locker from Blue Origin. The proposer has experience building for launch with Blue Origin, plus other suborbital providers as well.