photo credits: NASA
Up until 2015, if you wanted to drink coffee in space, you had to use freeze dried coffee crystals and something like an airtight Capri Sun pouch. If you have ever tried freeze dried ice cream, the kind you find at space camp or the Smithsonian, then you know that despite the very impressive advances in food & beverage technology, the product leaves something to be desired.
Making coffee in space comes with a unique set of challenges because every aspect of coffee consumption requires gravity - something in short supply on spacecraft. Gravity gives you the very popular pour over method. It also allows the coffee to drop into your cup and... stay there. These might be obvious to the casual observer of gravity, but the earthly force also helps perform several tasks we take for granted. Gravity influences the processes that cool your cup. It is even responsible for the stimulating scent of coffee wafting up from espresso foam.
According to Mark Weslogel, a fluid physicist at Portland State University, brewing espresso in the microgravity would be a far less sensory experience than at your local café. “On Earth, gravity is responsible for making bubbles rise and liquids fall. Such mechanisms vanish in the weightless environment of orbiting spacecraft,” he explains.
Many of the human factors of drinking coffee are hampered by space conditions. It’s no wonder the astronauts, who on average spend six months weightless, wanted to engineer a better way to bring the whole coffee experience into orbit with them. Not just to make coffee, but to savor it.
La macchina italiana (The Italian machine)
Enter the Italians who became the first to send espresso to space. The coffee company Lavazza and the Italian engineering firm Argotec collaborated with the Italian Space Agency to produce the world’s first extraterrestrial espresso machine.
Named after the International Space Station, the ISSpresso weighs 44 pounds, is the size of a microwave, and is an engineering marvel that manages to brew coffee in the extreme environment of microgravity. It does so by using a system of special pipes that can withstand extreme pressure and the same capsules Lavazza uses on Earth.
"Making coffee in space isn't easy," Argotec officials said. "This is the first capsule espresso machine that can work in the extreme conditions in space, where the principles that determine the fluid dynamic characteristics of liquids and mixtures are very different from those typically found on earth."
According to their press release, the machine works by “pouring” the coffee and, through a patented new system, cleans the final section of the hydraulic circuit. At the same time, it generates a small pressure difference inside a transparent pouch - the space "espresso cup” - so that when the straw is inserted, all the aroma of the coffee is released.
The specialized clear pouch keeps the cream and coffee separate until the astronaut can draw them together by straw, a setup which makes every sip a study in fluid dynamics.
Drinking coffee while orbiting 250 miles above Earth helps astronauts cope with homesickness and more. It expands our scientific knowledge. The design of ISSpresso and its espresso pouch allows researchers to apply the principles of physics and fluid dynamics that might help solve other problems of managing liquids in space at high pressure and temperature, such as rocket fuel transfers.
One Giant Leap
This brings us back to another milestone for coffee and science. On May the 3rd, 2015, just one day shy of May the 4th (be with you), the Space X Dragon capsule delivered ISSpresso to the attending crew. First to receive the heavenly espresso was Samantha Cristoforetti.
The opportunity gave rise to several sci fi references, all of which appeal to coffee and space geeks alike. As Cristoforetti took her first sip, astronaut Scott Kelly quipped, “That’s one small step for woman, one giant leap for coffee.” She then changed into a “Star Trek” commander’s uniform to pose for more photos, now using another specialized vessel, the zero-g mug designed by Mark Weislogel.
“We designed the Space Cup with the central objective of delivering the liquid passively to the lip of the cup. To do this we exploit surface tension … [and] the special geometry of the cup itself,” Weislogel explains.
Thanks to surface tension and fluid dynamics, when an astronaut connects her mouth with the lip of the cup, "a capillary connection is formed and the liquid travels up the vessel and forms sippable balls of coffee." [eater.com; cnn.com]
While gravity (or the lack of it) will still greatly impact the way astronauts can smell and taste their morning coffee, Weislogel and his team are hopeful that espresso cups will improve on the overall experience.
Each day, on the International Space Station the crew witnesses 15 to 16 sunrises. Since its debut mission, Isspresso has traveled more than 650 kilometers and seen 15,500 sunrises and sunsets. Now, thanks to the zero-g espresso cups, those sunrises will be enjoyed with an espresso.