US researchers have developed a 3D-printed zero-gravity espresso cup that will be sent to the International Space Station in February.
The Zero-Gravity Espresso Cup, developed by the Maseeh College of Engineering and Computer Science at Portland State University, is part of NASA’s Capillary Beverage Experiment, according to a statement on the university’s website.
The binding force between the water and the inner wall of the narrow tube pulls the edges of the water up, creating a curved meniscus.
The surface tension of the water inside the tube stretches to reduce the meniscus, which pulls the water farther up into the tube. The process stops when the liquid reaches mechanical equilibrium.
The narrow corner of the Zero-Gravity Espresso Cup and the mouth of the astronaut form a capillary connection. The surface tension automatically pulls the coffee towards the astronaut in low-gravity environments.
The design of the zero-gravity espresso cup debuted in November of last year and the cups will be tested before flying off to space.