Ever Wondered How Coffee Works in Space?

Here on Earth, enjoying a cup of coffee is a simple morning ritual, but in space coffee can be a bit more complicated. Curious to learn more?

Billions of people enjoy coffee every day; after all, it gives us that much-needed pick-me-up, a boost in mood, and a variety of health benefits. With so many ways to craft a great cup of coffee, it’s no wonder coffee is an incredibly high traded commodity. Each person has hers or his favorite method to make their cup of coffee, from cold brew, drip coffee, french press, to instant coffee.

However, for astronauts, enjoying a cup of coffee is a bit more complicated.

Why Drink Coffee in Space?

As you all know, coffee gives us drinkers energy, increased mood, and a variety of other benefits. Now imagine going a whole day without your daily coffee fix. And now imagine being in the weightlessness of space and conducting countless experiments and tests. Craving that coffee now? Astronauts, among missing family and friends, miss out on a variety of benefits that Earth, and its gravity, can give to us. Things such as dressing, taking a bathroom break, and drinking water and coffee, are vastly different tasks when placed in a zero-gravity environment. So, how exactly does an astronaut drink coffee in space?

How to Drink Coffee in Space

Before we get into how astronauts drink coffee, or liquids for that matter, in space, we must understand how liquid acts in a zero-gravity environment. In space, liquids tend to feature a sticky property and they often cling to surfaces and clump together. This is why you see water, or other liquids, floating in clumps during demonstrations.

Though it’s fun and interesting to see, this phenomenon makes enjoying a cup of coffee much more difficult when compared to drinking on Earth. Specifically, for mugs, due to the surface tension and capillary effects, the coffee would stick to the walls and bottom of the mug. No matter how you turn the mug, the liquid would remain ‘stuck.’ To solve this, astronauts use two methods: a bag or a ‘zero-g’ cup developed by fluid physicist, Mark Weislogel.

Let’s talk about the first method: sipping from a bag. Since the liquid is clumped into the bag, astronauts not need to worry about getting the liquid. This is because astronauts would simply suck on a straw to drink their coffee. Sound unappealing? We think so, too. Not only is drinking coffee from a straw unpleasant, but it also robs an important part of the coffee experience: aroma.

We all know that the smell of coffee, or any food for that matter, greatly affects how we perceive our meals. Specifically, with coffee, there are many different flavors and notes available. According to the Specialty Coffee Association of America, there is a coffee wheel, featuring a variety of flavors, tastes, and notes. Not only does the smell of the coffee affect how we perceive the taste, but it can also, as mentioned before, affect our mood. So with that in mind, drinking coffee from a bag is much less appealing; however, the second method of enjoying coffee, the ‘zero-g’ cup, allows astronauts to sip coffee in a more traditional way, while also experiencing the aroma of their brew.

The ‘zero-g’ cup works by capitalizing on the properties of liquids in a zero-g environment. Since liquids tend to stick and cling to walls, the zero-g cup features acute angles and a unique lip. When the liquid is placed into the cup, it piles and stacks right up towards the lip. This allows the drinker to easily sip and enjoy their cup of coffee. Furthermore, since the ‘zero-g’ cup is open, similar to a regular mug, this also allows astronauts to enjoy and experience the aroma of their brew. If you want to learn more about how the cup was made and how it works, check out this video. Now, with everything going on in the International Space Station, why exactly would scientists and inventors spend time researching coffee and other plants?

SpaceX is Sending Coffee and Cannabis into Space

We can all agree that coffee is enjoyable and, more often than not, a needed boost to get through the day. But is it generally a priority for the International Space Station? Probably not. However, what scientists are interested in is how plants grow in space and how they can be modified when brought back down to Earth. This is why SpaceX’s upcoming cargo to the International Space Station in March will contain the plant cultures for hemp and coffee.

With these plant cultures, scientists are hoping to gain insights into how the plants can adapt to the environment of space. Furthermore, they are hoping to gain knowledge of their ability to genetically modify plants when they come back to Earth. This knowledge would assist scientists in developing plants that could survive and thrive in harsher environments. Especially considering the impact of climate change, these studies would aid researchers in creating a stable source of plant-based food within different environments.

Freeze-Dried Coffee in Space

So, how exactly do astronauts make coffee in space? Well, there are two methods: freeze-dried coffee and the ISSpresso machine.

Let’s start with the more complicated method: the ISSpresso machine. As the name implies, this machine creates espresso for astronauts to enjoy. However, due to the absence of gravity, creating, working, and maintaining an espresso machine is a bit more complicated.

On Earth, regular espresso machines heavily rely on gravity. The presence of gravity allows a variety of phenomena to take place. For instance, when water is boiled on Earth, bubbles of steam are evenly dispersed in the water. However, in space, these steam bubbles clump together, preventing an even distribution of temperature within the liquid. Additionally, gravity also helps the liquid in espresso machines move from one location to another. To adapt to zero-gravity, engineers implemented steel tubes instead of the typical rubber tubes present in espresso machines. In addition to temperature controls, these features allow the ISSpresso machine to create a shot of espresso. Sound complicated? Yes, we know. Currently, the ISSpresso machine is being further developed for regular use within the International Space Station. In the meantime, astronauts have access to another method of creating a cup of coffee: freeze-dried instant coffee.

With the complications of zero-gravity, freeze-dried instant coffee provides a simpler approach to making a cup of space coffee. After all, one simply needs to add hot water to the instant coffee and, voila, a cup of coffee is made! How exactly does this happen, though? Well, to make instant coffee, there are two methods: freeze-drying and spray-drying. At Waka Coffee, we freeze-dry our coffee, allowing for maximum flavor.

To make freeze-dried coffee, the coffee beans are ground and brewed into a concentrated liquid, similar to honey. After being filtered, the concentrated brew is then frozen to about -50 degrees celsius. After being frozen, the primary sublimation process begins. Essentially, sublimation is the process in which ice changes into steam without defrosting. After this phase, water molecules are removed from the product, creating freeze-dried granules. Then, after that, you just need to add hot water and enjoy! Instant coffee makes even coffee in space easier.

Do Astronauts Even Want Coffee in Space?

Oh yes, they love it so much! In fact, Bill Shepherd, the commander of Expedition 1 of the International Space Station proposed that coffee will receive its own storage locker in the station after the brew ran out halfway through the nearly five-month mission in 2000-2001! Here are some quotes from the Expedition One December Crew Log discussing the important issue of... coffee.

"Already drank all the coffee that 4A brought up, but going to order a bunch more on 5A when the lab comes. We root around through the chow boxes and find some more. "Alpha" really needs a "coffee-barka" (translation-coffee locker) somewhere onboard."

"Say hello to Sergei G. and look for some hot water. Everyone's real happy that we got a bag full of instant coffee and tea drinks from 4A. We are wondering if we should put another order in for 5A."