NASA to Look at Coating in Slosh Experiment
NASA researchers will soon deploy the Slosh Coating investigation, which will test a liquid-repellant coating inside a container in micogravity.
Currently, several problems arise with how fuel is forced out of tanks in a low-gravity environment, according NASA. For example, spacecraft use several pieces of mechanical equipment that are not only heavy, but can break down and are ultimately unreliable.
“The sponges, vanes, baffles and other structures placed inside fuel tanks to move liquid where it is needed are all susceptible to breakage,” said Brandon Marsell, NASA’s Launch Services Program principal investigator. “If we can replace these complicated metallic mechanisms with a coating, it will reduce the potential for things to break, as well as save weight and money.”
In addition to reducing costs and increasing the performance of the tanks themselves, getting the formula right for a coating might also eliminate fuel waste.
When cryogenic propellants spread out over tank walls, the heat on the outside of the tank can boil off the propellant. Coating the walls of the tank with a repellant that would allow for the fuel to “gravitate” to the sump at the bottom of the tank would increase overall efficiency if everything reacts how scientists anticipate.
The investigation aims to make sure those anticipations are correct, and is modeled after the SPHERES-Slosh Investigation that began in 2013 (and is also slated for one more run in the near future).
“We know the coating will repel water, but we aren’t sure what the fluid will do instead,” said co-investigator Jacob Roth, who is also with the LSP. “We think it will bounce off the walls and stick to the bottom of the tank, the sump, where there is no coating. One question this test might answer is how well it sticks, how easy or difficult it is to dislodge the liquid from the sump when it sloshes around.”
NASA suggests that understanding the function of liquid-repellant coatings in space might help with how they’re developed for use on Earth as well, and could lead to better transportation-related advancements such as preventing rain from blocking the view through windows on automobiles and aircraft.