Carthage College

CARTHAGE COLLEGE (2015, 2016 & 2017)

The Modal Propellant Gauging (MPG) project is a collaboration between Carthage College and the NASA Kennedy Space Center Cryogenics Laboratory to develop a high-resolution low-gravity fuel gauging technology by exploiting the effect of fluid loading on the structural properties of liquid-filled propellant tanks. Traditional fuel gauging is ineffective in the reduced gravity environment of space. Propellant slosh and the propensity of liquids to adhere to tank surfaces in reduced gravity make low-gravity gauging problematic. While several approaches to low-gravity propellant gauging have been demonstrated in the years since the Apollo missions, all suffer from reduced accuracy at low fill levels where accuracy is most critical. At current prices of over $10,000 per lb of launch mass, the additional propellant required to mitigate against gauging errors results annually in tens of millions of dollars in additional mission costs across the industry.

The MPG experiment has demonstrated gauging accuracies of 1% or better in settled 1-g conditions. Through parabolic testing on the Zero-G aircraft, unsettled zero-g gauging accuracy is approaching 2-3% of tank volume, well within the NASA target of 5% gauging accuracy for unsettled propellant.

This work is supported by the NASA Flight Opportunities Program through grant NNX15AJ90G and by the Wisconsin Space Grant Consortium.

PI Kevin Crosby and Assistant Stephanie Finnvik attend the MPG Experiment during a zero gravity parabola.

PI Kevin Crosby and Student Tessa Rundle present the MPG Experiment at NSRC 2016.