Since the early days of space travel, a consistent complaint has been of drinking coffee in a cup. It was not an easy task for astronomers to have a cup of coffee, while they were in space. Pouring hot coffee into cups is a dangerous task. Fluids behave in a very different way outside of Earth’s atmosphere. Drinking coffee in the microgravity environs of space is a tough proposition.
There’s no top, no bottom, no up and down, no sideways,” Mark Weislogel studying fluid dynamics at Portland State University said in between communication with the astronauts at the International Space Station. Hence, an experiment carried out by astronauts at the International Space Station was focused at designing a cup for space travellers by dealing with minimal gravity using capillary action. Weislogel has exhibited various breakthroughs that should make coffee and other liquids, much easier in the absence of gravity. A new cup, designed particularly for astronauts, would make it possible for them to pour hot coffee and enjoy it.
The mechanism for capillary action is provided by the liquid’s surface tension and the adhesive forces between the solid and liquid.
Weislogel and his colleagues have been conducting Capillary Flow Experiment-2 (CFE-2) to illustrate how fluids move up surfaces in microgravity settings. The zero-gravity coffee cup is one of the offshoots of this project, developed in collaboration with astronaut Don Pettit.
The team made the cup with an interior corner”, which works on the principal that, even in microgravity, liquid will naturally flow along the intersection of two surfaces if those surfaces join at a sufficiently narrow angle. It is being said that the cup when positioned with lips, rightly, allows the coffee to pass along the corner through capillary action. An astronaut is then able to consume it.
With the zero-gravity cup, “As you sip, more fluid keeps coming, and you can enjoy your coffee in a weightless environment,” said Pettit. “This may well be what future space colonists use when they want to have a celebration.”
Astronaut Don Pettit was told to try it on-board the space station. Weislogel said that it became the first patent then, brought to practice in orbit.
This device will be particularly significant for fluid systems on spacecraft, like the water purification systems, in which liquids must be passively separated from gases in a zero-gravity setting.