Watch: NASA Video Shows How Water Behaves in Space
As part of a series of experiments to determine exactly how water behaves in microgravity, NASA has released a video that shows the weird, counterintuitive ways fluid behaves in space, which often resembles a Jello-like gelatinous goo:
NASA has begun conducting the SPHERES-Slosh experiment, which explores the differences between fluid behavior on Earth versus fluid behavior in space, on the ISS. NASA rockets use liquid propulsion fuel when they are set off, but the unpredictability of fluid behavior in space puts the safety of those rocket launches at risk.
"Modern computer models try to predict how liquid moves inside a propellant tank," said Brandon Marsell of NASA's Fluid Group at the Kennedy Space Center. "Most of the models we have were validated under 1G conditions on Earth. None have been validated in microgravity."
"The International Space Station provides the perfect environment to conduct liquid behavior studies in microgravity," said principal investigator Paul Schallhorn. "So we have designed an experiment that simulates how rocket fuels move around inside their tanks."
In order to study fluid behavior in microgravity, the researchers at Kennedy built a liquid chamber flanked on either side by robots, which shake and move the chamber in order to mimic common turbulent movements of a spacecraft. The chambers were filled with 20%-40% fluid, in order to imitate a partially used fuel tank, and they used water in their trials, as it acts very similarly to the rocket propellant hydrazine.
"We are getting great data," Marsell said. "So far, our computer models on Earth have done a good job predicting wave motions inside the chamber."
According to Schallhorn, there has only been one major surprise yielded from their data thus far: bubbles. "The way bubbles form and interact inside the chamber is surprising - and not predicted by our models. We were taken off guard with what we saw in the data."