Researchers Demonstrate Liquid Transfer Equipment for Apollo 14 Test

Two researchers at the National Aeronautics and Space Administration (NASA) Lewis Research Center demonstrate the test equipment they devised to study the transfer of liquid in microgravity onboard the Apollo 14 mission. The test was an early step in developing the ability to transfer liquids from a tanker vehicle to spacecraft in space. Researchers needed to know the tank’s outflow characteristics, the fluid’s behavior when entering new tank, and the effects of accelerations. Others had performed some calculations and analytical studies, but no one had examined the complete transfer from one tank to another in microgravity. The early calculations concluded that the transfer process was impossible without devices to control the liquid and gas. This investigation specifically sought to demonstrate the effectiveness of two different surface-tension baffle designs. The experiment was an entirely closed system with two baffled-tanks. The researchers also built a similar device without the baffles. The experiment was carried onboard the Apollo 14 spacecraft and conducted during the coast period on the way to the moon. The two surface tension baffle designs in the separate tanks were shown to be effective both as supply tanks and as receiver tanks. The liquid transferred within two percent of the design value with ingesting gas. The unbaffled tanks ingested gas after only 12-percent of the fluid had transferred.