What It Takes To Make A Decent Cup Of Coffee In Space
When our pals at the Two-Way wrote last month that
engineers had finally come up with a way to brew some good Italian
espresso on the International Space Station, we were thoroughly
As they reported,
the space-age coffee machine — called, naturally the “ISSpresso” — is a
capsule-based brewing system. It’s similar in principle to a Keurig
machine. But engineers at the Italian aerospace firm Argotec, along with coffee company Lavazza and the Italian space agency, ASI, finessed it to function in a microgravity environment.
Just when did space get so hipster? First they the start growing their own salad and vegetables up there, and now they’ve got fancy coffee — what’s next, a microbrewery on Mars?
But mainly, we wondered — why is it so complicated to make coffee on the ISS? To help answer that question, we called up Vickie Kloeris, the manager of the NASA Space Food Systems Laboratory.
“You can’t just send a regular espresso machine to
orbit and expect it to work,” she says. Here on Earth, coffee machines
depend heavily on gravity, she explains. But on the ISS, there’s only a
minuscule amount of gravity — called microgravity. So everything floats.
The biggest challenge is figuring out how to keep the
scalding water inside the espresso machine contained, Kloeris says.
Everything has to be sealed, secure and safe.
There’s also the issue of keeping everything
sanitary. “On the ISS, they don’t have a sink where they can wash
everything up,” she says. A small amount of liquid left over in the
machine could become rank and unhealthful pretty quickly.
But once these safety concerns are addressed, there’s
the whole issue of making sure the espresso tastes good. And that where
it gets really tricky, says David Avino at Agrotec, who helped develop the ISSpresso.
“To make good Italian espresso there are two major
components — the pressure and the temperature,” Avino says. Water has to
approach the coffee grounds at around 98 Centigrade (208 Fahrenheit),
and leave the brewing unit at 75 C (167 F), Avino says. Fluctuations in
the temperature of either the water or the steam can leave you with a
But the balance is really hard to achieve in space.
When you boil water on Earth, the bubbles of steam stay evenly
distributed in the water because of gravity. In space, these bubbles can
come together and create pockets of really hot air.
That can really mess with the temperatures inside the espresso machine, Avino says. It can also get dangerously hot.
The engineers behind the ISSpresso got around this by
using sturdy steel tubes to move the water around, instead of the
rubber tubes used in regular espresso machines. They also equipped it
with various temperature controls.
These extra bells and whistles make the ISSpresso
weigh over 40 pounds, according to Avino. The plan is to send the
machine up to the ISS with Italian astronaut Samantha Cristoforetti next year.
Initially, the machine will come with only 20
single-serve coffee capsules. “Our machine is still an experiment,”
Avino says. If all goes well, he says, the machine could become a
permanent addition to the space station.
Of course, drinking coffee up in space still won’t be
the same as sipping it down here on Earth. Classic Italian espresso
comes with a creamy layer of foam on top. But that foam may behave a lot
differently in space, Avino says. “It will most likely spread around
the whole container.”
And the astronauts will have to drink it out of a
sippy pouch so the hot liquid doesn’t float away from them. It’s not
quite as elegant as drinking from an espresso cup.
It also means the astronauts won’t be able to smell the coffee very well, Avino says. And smell has a huge impact on the way we perceive food and drink.
But hopefully, it will be an improvement over the
instant coffee that the astronauts have been drinking thus far. With a
shot of sharp espresso to start the day, Avino says, “they’ll live much,