How astronauts drink coffee at the International Space Station

We often do not give much importance to routine everyday things. However, what may seem simple here on Earth becomes a completely new challenge when we are in space.

The effects of microgravity make things work differently, as they do here on Earth, in normal gravity. For example, making a cup of coffee becomes a complex process that requires systems specially designed for that task.

Which leads us to wonder, how do astronauts drink coffee when they are in space?

In the official YouTube account of the European Space Agency (ESA), British astronaut Tim Peake shows how coffee is prepared onboard the International Space Station (ISS). The process begins by taking an aluminum package from a storage compartment on the walls of the ISS. Since things simply float in microgravity, you can’t have conventional shelves or cupboards to store food and drinks.

In space, you can’t put water in a cup either, in microgravity the water turns into floating balloons instead of sitting in a cup waiting for you to drink it as it does on Earth. The ISS coffee maker is a hot water injection system.

You can see in the video that astronauts must place the aluminum package in the hot water machine, and then press a button to inject water into the aluminum package. Water dissolves coffee (presumably lyophilized), cream and sugar substitute, and the astronaut drinks coffee with a straw, which has a built-in unidirectional valve, to prevent the liquid from escaping.

ISSpresso is the first espresso machine designed for use in space, produced by the companies Argotec and Lavazza in a public-private partnership with the Italian Space Agency (ASI).

The first notable difference of the ISSpresso refers to the size and weight: 43 × 42 × 36 cm (17 × 16.5 × 14 inches) and almost 20 kg (44 lb). The hydraulic circuit ducts are made of steel, not plastic, to withstand operating loads of up to 400 bar (5,800 psi).

The machine has conditions of use that are similar to traditional ones, to facilitate the operations of astronauts without the need for specific training. After verifying that the water container is installed correctly, the astronaut inserts the coffee capsule into an opening at the top of the machine, then closes the small door and selects the size of the drink. After that, they place the beverage bag in the adapter and begin the coffee preparation process.

The first espresso coffee prepared in space was made by Italian astronaut Samantha Cristoforetti on May 3, 2015.

That is why after long years of research and studies on the behavior of fluids in microgravity, Portland State University engineers have made progress, the Zero-G cup.

The new design makes it possible to enjoy espresso coffee and other drinks in the low gravity environments of spacecraft. Without the force of gravity, fluids behave very differently from the earth. Instead of pouring, a liquid retains a globular shape joined by its surface tension. This phenomenon complicates even the most basic actions, such as drinking a cup of coffee and tilting it to drink.

This cup was presented at the Division of Fluid Dynamics of the American Physical Society, from November 23 to 25, 2014, in San Francisco, California and is available in two sizes, 150 ml (5 fluid ounces) and 60 ml (2 fluid ounces).