The International Space Station received one heck of an early Christmas gift from an Italian astronaut who arrived last week: the first espresso machine in space. Look, it’s important to have caffeine everywhere you go.
As of right now, the astronauts aboard the ISS are consuming the beverage through plastic pouches that remind me of my Capri Sun drinking days (I bet the astronauts’ straws don’t make the pouches explode everywhere). That’s fine, but it’s apparently not the best possible way to enjoy the space espresso. Some physicists in Portland presented a paper titled The Capillary Fluidics of Espresso at the 67th Annual Meeting of the APS Division of Fluid Dynamics, and in it, they describe another way. They designed a cup and 3D printed a sample that’s suitable to use in space and would improve the espresso drinking experience.
Author Mark Weislogel explained to Gizmodo that the cup design focuses on capillary wicks:
According to Weislogel, it’s all about using surface tension to pull the espresso along the walls of the cup towards the opening. You’ll notice the unusual folded geometry of the vessel—those corners are a crucial part of what brings the espresso to the drinker’s mouth, by exploiting their abilities as “capillary wicks,” which draws the coffee along the walls of the container as the drinker sips. When you bring it to your lips, he explains, “it makes a capillary connection such that when you remove liquid into your mouth more liquid is drawn along the interior corner in a way of resupply.”