Abby Wilbourn, Department of Mechanical Engineering, CSU, Wallops Flight Facility Presentation, June 18, 2010

No current, acceptable solution exists to determine liquid volume in a tank exposed to microgravity, without some form of liquid settling, tank stirring or spacecraft acceleration.

Current mass gauging sensors add significant weight to propellant tanks.

An optical mass gauge is a viable option, which will allow accurate, real-time liquid volume measurements in any gravitational environment.

At the heart of the sensor exists an interferometer that measures the pressure change created by a small piston.

The piston first pressurizes a reference volume, and then pressurizes the unknown tank ullage. Using equations of simple interferometry and the ideal gas law, the unknown tank ullage can be solved for, yielding the unknown liquid volume.

Two tanks with different volumes of liquid are independently exposed to reference cell. The amount of liquid in each can be determined; the two tanks represent fuel/fluid levels at different periods during a mission.

The Colorado State University Optical Mass Gauge has demonstrated its ability to measure a liquid volume to within 2% in the laboratory environment.

The sensor is constructed using single-mode fiber optics.

The flight ready payload has survived a rigorous vibration test provided by Sierra Nevada Corporation.

The team cannot be here but sends their greetings! Here is what they are doing:

Ryan M. SullenbergerNow affiliated with NASA – MSFC and Princeton University.

Wesley MunozNow affiliated with Abound Solar.

Kenny VogelNow affiliated with Woodward Governor.

Matt LyonNow affiliated with the Naval Shipyard at Pearl Harbor.

Dr Azer Yalin, Brian Lee, Lei TaoDr John WilliamsDr Sachin Joshi

Dr Kurt PolzinDr Valentin Korman

Dr Joseph Pesce

Jason Priebe, Dan Goodrich andLad Kurtis

Azer Yalin