Modal Propellant Gauging - Propellant Refueling and on Orbit Transfer Operations

Abstract

Since 2011, students have been working in collaboration with NASA Kennedy Space Center and NASA Johnson Space Center on a fuel gauging method for spacecraft called Modal Propellant Gauging (MPG). MPG has seen many iterations over the last decade for improvement to the technology. The Modal Propellant Gauging - Propellant Refueling and on Orbit Transfer Operations (MPG-PROTO) project is a continuation of the Modal Propellant Gauging (MPG) project. The current design for the Power and Propulsion Element involves spherical tanks that have 3 ports, one for draining, one for filling and a third for equalizing pressure, referred to as the ”vent port”. A concern arises with the vent port that at low fill levels, the liquid will coat the vent port and send dangerous fuel into space that could potentially cause erosion to Lunar Gateway. In attempt to remedy this issue, MPG-PROTO is implementing a Propellant Management Device that will serve the purpose of guiding the liquid away from this port. The purpose of MPG-PROTO is to prove the accuracy of the MPG technology while simulating refueling environments with a sub-scale tank and flowing liquid in low gravity. If successful, MPG will be on-board the SLS/Orion Missions, the Gateway Power and Propulsion Element (PPE) and the ascent modules from the lunar surface back to the orbiting Gateway station.