For many, the day begins only after the first sip of coffee. But what if you are 400 kilometers up on Earth, where gravity doesn’t play along? NASA astronaut Don Pettit was confronted with this challenge on the International Space Station (ISS) and chose to get creative.
Unlike on Earth, where individuals drink coffee from a hot cup, astronauts historically use sealed pouches with straws to avoid liquids floating off in microgravity. But Pettit yearned for the entire coffee experience—scent, flavor, and the reassuring touch of an actual sip.
The Birth of the Zero-G Cup by Don Pettit
To address this, Don Pettit created the Capillary Cup, a unique container that resists weightlessness, enabling astronauts to sip coffee normally. Based on the Rochester Institute of Technology, this invention employs capillary action to flow the liquid to the astronaut’s lips without needing gravity.
In a now-viral X (formerly Twitter) video, Pettit is enjoying coffee from his floating white cup. “Having a sip O’joe in the morning; nothing beats the zero-g cup for morning coffee,” he captioned the photo.
Having a sip O’joe in the morning; nothing beats the zero-g cup for morning coffee. pic.twitter.com/koM2V4Lhsf
— Don Pettit (@astro_Pettit) March 27, 2025
Improving the Space Coffee Experience
Coffee aficionados understand that flavor is only one aspect of taste—it’s an experience involving all the senses, particularly smell. Pettit resonated with that when he responded to a question from a user who asked if a cup in space was really necessary.
“The zero-g cup enables you to smell your coffee, something you can’t do when drinking out of a straw from a bag; the smell is likely 70% of the coffee pleasure,” he explained.
The zero-g cup allows one to smell your coffee, something you can’t do when sipping through straw from a bag; smell is probably 70% of the coffee pleasure
— Don Pettit (@astro_Pettit) March 27, 2025
His lighthearted approach to space habits also became popular. When one of the users commented on how people are generally asked not to play with their food, Pettit replied, “In space, you can play with your food and call it science.”
In space, you can play with your food and call it science
— Don Pettit (@astro_Pettit) March 27, 2025
A Temporary Setback for Space Coffee
Although the Zero-G Cup was a success, astronauts have recently encountered a setback. On March 22, Pettit announced that the ISS’s espresso machine had been returned to Earth, and astronauts now only have instant coffee. Although this is not great for coffee lovers, Pettit’s invention is still a major step forward in enhancing space living conditions.
His Capillary Cup not only improves the astronauts’ coffee-sipping experience but also helps improve our knowledge of fluid dynamics in microgravity, advancing the frontier of space science and comfort.
