NASA SBIR 2004 Solicitation


PROPOSAL NUMBER: 04 X6.05-8229
SUBTOPIC TITLE: In-Space Propulsion (Chemical/Thermal)
PROPOSAL TITLE: A Propellant Mass Gauge

SMALL BUSINESS CONCERN (Name, E-mail, Mail Address, City/State/Zip, Phone)
Advanced Technologies Group, Inc.
641 SE Central Parkway
Stuart, FL 34994-0000

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
John Justak
641 SE Central Parkway
Stuart, FL 34994-0000

Advanced Technologies Group, Inc. proposes the development of a Liquid-Oxygen Mass Gauge, (LMG) for In-Space cryogenic storage capable of continuous monitoring of liquid quantities to better than 1% accuracy. The proposed sensor builds on previous liquid hydrogen sensor development successes and patents. It can be utilized to measure cryogenic propellants, and sub-critical cryogenic fluids in use on a wide range of space applications and in ground applications to monitor fluids ranging from liquid oxygen to MMH and N2O4. The LMG can also indicate the presence of contaminants such as nitrogen used to purge the system. The current methods use either wire resistance measurements, capacitance or point sensors, combined with pressure and temperature measurements. The LMG will be lighter, require less energy to operate, and provide less heat leak than existing technologies. Current techniques will not function correctly in boiling or stratified liquid cryogens or in reduced gravity. During phase I, Proof-of Concept experiments will be performed with liquid oxygen. Commercial applications in the home health care industry have been identified.

Within the past few years, many technical reviews have indicated the need for advances in zero-g level sensor techniques. The absorption meter design lends itself well to a potentially low cost design. The tank could easily be made from any of the currently used metallic alloys used for the manufacture of cryogenic storage, and depending on the specific wavelength of light used for the optical attenuation measurement, inexpensive solid state electronics could make up the balance of the instrument . Test stands across the country constantly have troubles determining the levels of cryogen remaining in the tank.

Advanced Technologies Group has recently been investigating a liquid oxygen sensor for home health care, in the area of oxygen therapy. Currently, several home health liquid oxygen tanks utilize differential pressure measurements to determine liquid oxygen level remaining in the tank. This method is expensive, less accurate, and it biggest detriment to the system is the amount of heat leak introduces through the extra tubing. Existing market is over 30,000 units per year total.