Liquid Hydrogen Microgravity Flight Experiment Concept

Abstract

A technological breakthrough is needed in the area of zero-g hydrogen management capabilities to enable future NASA, Air Force, and commercial missions, which all depend on liquid hydrogen and oxygen, the highest energy liquid rocket propellants available. In terms of liquid hydrogen fluid transfer, slosh, storing and dumping, there has been very little or no flight technology demonstrations applicable to the current needs of NASA, the Air Force, and the commercial sector. In order to enable the efficient, reduced risk, and low cost missions necessary in today’s austere space program environment, it is crucial to provide the fluid technologies needed for current and advanced upper stages and future hydrogen-fueled vehicles. This technology will allow launch systems to provide greater payloads at a reduced cost through more efficient zero and low-gravity handling of cryogenic propellant liquids in launch vehicle tanks. A design concept for a four-tank arrangement, packaged to perform the major objectives of subcritical liquid hydrogen handling experiments in zero-g, is presented, and is capable of fitting into several candidate NASA carriers. The baselined COMET (Commercial Experiment Transporter), launched on the Conestoga launch vehicle, would function as a free-flying experiment for at least three months at a microgravity environment of 10^-5 g’s or lower.¹ The completion of this experimental program will advance the state-of-the-art in the technology areas of cryogenic fluid transfer, storage, and slosh control dynamics in microgravity environments.