Carthage College’s Propellant Mass Gauging in Gateway Architecture Vehicles experiment includes new spectral density (SDM) and point sensor methods (PSM)—extensions of its modal propellant gauging (MPG) process—that support fluid mass measurement under varying pressures. These new approaches to propellant gauging do not rely on instantaneous measurement of modal frequencies as a proxy for contained mass. They may be more reliable methods of gauging during high-rate tank drains under acceleration and during propellant transfer, engine burns, and other dynamic mission phases.

This work is a continuation of previous flight testing under T0123, T0147, T0160, and T0191. 

Problem Statement 
NASA’s Space Launch System (SLS) rocket and Orion spacecraft as well as commercial partners have a need for a low-gravity propellant mass gauging concept that provides robust mass measurements during dynamic events that involve changes in tank pressure, such as engine burns. The researchers will use parabolic flights to validate MPG/PSM during continuous drain operations in microgravity, which is expected to provide initial data on the method’s sensitivity bounds during high-rate drain. A vertical-takeoff and vertical-landing suborbital flight will seek to validate the SDM for 0-g settled gauging, with a goal of demonstrating independence from tank pressure, which affects thin-wall vessels.
 

This technology may reduce the margin of error in measuring propellant levels as well as potentially reduce fuel margins, which could allow for more fuel to be used for a given tank. This would benefit NASA missions, the commercial space industry, and other government agencies.

Future Customers
• NASA missions, notably Orion and the SLS rocket
• Human space exploration missions
• Commercial and military satellite providers
• Launch services providers
• Developers of on-orbit fuel depots