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How Do Astronauts Drink Coffee in Space?

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What it Takes to Make a Decent Cup of Coffee in Space

When astronauts head to the International Space Station—anywhere between 205 and 270 miles above us—they leave behind a lot of luxuries, including fresh air, long showers and fresh, steaming pots of coffee. 

Imagine doing your job every morning without coffee. Nothing would get done, and you'd be an angry, irritable mess. Well, astronauts are no different. So they do what they have to do—they drink freeze-dried coffee through a straw in a sealed plastic bag. That's what led Death Wish Coffee to create an instant blend of freeze-dried coffee to send to the International Space Station.

Astronauts can also get a good cup of coffee by using the ISSpresso machine.

An ISSpresso machine used in outer space by NASA astronauts.[Photo source: NASA]

What is an ISSpresso Machine?

ISSpresso—aptly named for the International Space Station—is what astronauts use to make coffee, tea, broth or other hot beverages they might enjoy. Water at room temperature is heated and, under pressure, used to create an espresso for the astronaut. The ISSpresso is not much larger than a typical espresso machine you'd find in your local coffee shop. 

Unlike other foods and drinks in space, coffee made with the ISSpresso machine does not have to be consumed from a plastic bag. Instead, they use a zero-G coffee cup.

"If you tried to use a regular coffee mug, you might not get the coffee to your face...it would be trapped at the bottom of the mug,” fluid physicist Mark Weislogel, of Portland State University and IRPI LLC, who helped invent the cups, told NASA in an interview.

In low-gravity environments like the ISS, fluids tend to get "sticky" because of surface tension and capillary effects—as a result, coffee tends to cling to the walls of the cup. 

“You could dip your tongue in the cup, and lick the hot coffee out. Or you could throw it out of the cup and suck down the scalding blob that forms in the air," Weislogel continued in his interview.

The zero-G coffee cup, however, solves this problem by putting the behavior of fluid in microgravity to work. The liquid piles up at the lip of the cup and flows as you sip. It wouldn't work on Earth because of the scientific design behind it but gives astronauts the fuel they need in space. 

Astronauts are making leaps in the name of science—if anyone deserves a strong cup of coffee, it's them. Which is exactly why you'll find Death Wish Coffee on NASA's permanent menu.

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