Any coffee lover will tell you that one of the first things they do when arriving in a new place, such as a hotel room or an Airbnb, is to assess the coffee brewing equipment. For the less discerning, instant will do, while others live in the hope of finding a French press, filter coffee machine, or capsule espresso machine provided, or at least a coffee shop nearby.
For astronauts aboard the International Space Station (ISS), coffee quality is probably fairly low on the priority list, well below issues of safety, mission success, and scientific discovery. Yet just like the rest of us, astronauts care about creature comforts, which for many includes a decent cup of coffee. Unfortunately, in a microgravity environment, coffee brewing options are limited and have historically been limited to instant (soluble) coffee.
All that changed in 2015, when the iconic Italian coffee company Lavazza helped to design a machine that could prepare and dispense espresso in space. Fittingly, the first astronaut to use the machine was Samantha Cristoforetti, the first Italian woman in space. She tweeted a photo of herself wearing a Star Trek uniform and enjoying fresh espresso with the caption “Coffee: the finest organic suspension ever devised. Fresh espresso in the new zero-G cup! To boldly brew …”
The 44-lb (20-kg) machine, nicknamed ISSpresso, was a joint effort between Lavazza, the aerospace engineering firm Argotec, and the Italian Space Agency (ASI). The flight model that ultimately went into space was the fourth iteration of an 18-month project that required NASA oversight for the safety of the hardware. ISSpresso arrived with a shipment of 15 espresso coffee capsules and five capsules for flushing the hydraulic system on the uncrewed SpaceX CRS-6 resupply mission in April 2015.
Along with preparing short black and long black coffees, it could also prepare hot tea and broth for rehydrating space food (no luck for latte or cappuccino lovers). Six specially designed 3D-printed microgravity coffee cups accompanied the machine, allowing the astronauts to drink the espresso with the help of capillary action .
In addition to providing the astronauts with fresh espresso, the machine also served as a scientific payload, focusing on fluid dynamics at high temperatures and pressures in the context of microgravity. Preparing espresso in space was no small challenge, as the brewing process relies on using pressure to force nearly-boiling water through finely ground coffee. The movement of the coffee in the microgravity cups provided valuable insights about the behaviour of complex fluids in orbit and the nature of foam formation in space.
To boldly brew:
- Cristoforetti had already been on the ISS for nearly six months before getting to enjoy her "zero-G" espresso. The ISSpresso machine had been scheduled to arrive in January 2015, but was delayed until April due a shipping backlog. Cristoforetti returned to Earth in June 2015 aboard a Soyuz spacecraft at the conclusion of ISS Expedition 42.
- Soon after being used by Paolo Nespoli to celebrate International Coffee Day on 30 September 2017, The ISSpresso machine completed its “mission” in December 2017 and was flown home by SpaceX CRS-13.
- Although using the machine was not radically different from a commercial espresso maker on Earth (install water container, insert capsule, close door, select drink size, attach drink pouch, brew, drink), the internal operations varied significantly from a normal Lavazza machine to ensure its function and safety in space. The hydraulic circuit ducts were made from steel rather than plastic due to the huge amount of pressure required. It was also designed to efficiently use water and avoid leakage.
