Assessment of prediction and efficiency parameters for cryogenic no-vent fill

Future long-duration crewed and robotic missions will require efficient methods with which to transfer cryogenic propellant from a depot storage tank to a customer receiver tank in the microgravity of space. Because unsettled cryogenic liquid cannot be transferred in microgravity with the vent valve open, the receiver tank must be prechilled to some target temperature that is sufficiently cold to then allow a non-vented fill (NVF). Predicting this target temperature is difficult, however, but can be done. A predictive parameter based on 1st Law from Kim et al. [13] is extended to include parasitic heat leak as well as initial fill levels to permit an assessment across the consolidated NVF and no-vent top off database. An efficiency parameter is also proposed to determine efficiency of a given injection method/tank pair. The prediction parameter is applied to 158 historical tests over a wide range of fluids, injection methods, and tank geometries. Additionally, a parametric study is conducted to determine the influential factors that affect NVF. Results indicate a 100% success rate that the parameter can predict the failure of a non-vented transfer for a given initial state and desired final state.

Automated summary

Efficient methods for transferring cryogenic propellant in microgravity were explored, with successful prediction of non-vented transfer failures through predictive and efficiency parameters. This research provides valuable insights for future long-duration crewed and robotic missions.