Astronauts may soon be able to enjoy Zero-G style espressos with the help of a specially designed cup. An espresso machine will be sent to the ISS designed by the Italian company Argotec. Its only inconvenient would be that the ISSpresso serves the coffee in a pouch and the astronauts have to sip it with a straw, which does not offer the same pleasure as drinking espresso from a little coffee cup does on Earth.
A team of researchers aimed to solve this problem by crafting a special cup that allows the astronauts to drink their beloved beverage in a manner similar to that used by the rest of Earth’s inhabitants. Their concept was to replace the role of gravity with the forces of surface tension.
Mark Weislogel, professor in the Thermal and Fluid Sciences Group at Portland State University, Drew Wollman, his researcher colleague and high school student Nathan Ott presented their research regarding the espresso experience in free-gravity areas at the American Physical Society’s Division of Fluid Dynamics Meeting in San Francisco,on November 24.
One of the unique features of espresso is its low-density colloid of emulsified oils, which rise to the surface and form the beloved foam or the “crema”. As gravity has a crucial role in the process, the team of researchers tried to figure out an alternative for the zero-gravity areas.
The team conducted by professor Weislogel made specific measurements for assessing the effects of surface tension and wetting for “Italian” espresso, caffee Americano and caffe latte.
Taking into consideration the importance of the “crema” texture and aromatics for most people, the researchers created an “espresso space cup”, which is thought to have an abnormal design, but which can contain liquid coffee by making use of surface tension.
“Its geometry is the ‘smart’ part, which operate the fluids-control system without requiring pumps or centrifugal forces.”,professor Weislogel said.
The cup was designed especially for coffee, which contains a relatively high percentage of oil from the beans, ensuring a superior viscosity level and consequently, stronger surface tension.
Rapid drop tower tests were applied to the cup to ensure that, under simulated microgravity conditions, coffee remains inside, while the manufacture of the cup implied the use of special 3D printers.
The researchers won’t stop here, they aim to design advanced equipment for astronauts, considering that the era of the ISS is the perfect time to make advantage of the available tools.
Weislogel explained that him and his team are striving to use their new discoveries for reassessing all fluid systems related to spacecrafts, such as cooling systems, water processing equipment, habitats of the plants and animals, food, medical fluids and so on.