A New Geometric Shape Travels to the International Space Station

A geometric model developed through a collaboration between the University of Oxford and the Budapest University of Technology and Economics has just become the focus of one of the most remarkable experiments ever carried out in space. These “soft cells” are geometric forms capable of filling space without straight edges, and they also appear in biological structures. One of them, the f2 variant, was sent into space, and its behavior in microgravity surprised even the astronauts.

Soft cells were described in 2024 as a new class of geometric shapes that fill space without relying on sharp vertices. Their geometry resembles that of a polyhedron, but with one key difference: the faces do not need to be flat and the edges are not necessarily straight. In the f2 variant, the surfaces are “minimal,” similar to those formed when a soap film stretches across a wire frame, as shown in the image below.

The Geometric Shape Discovered in 2024

This feature caught the attention of the Hungarian space program HUNOR, which proposed bringing a structure shaped like the edge of the f2 cell to the ISS as part of the Axiom-4 mission. The goal was to fill it with water in microgravity and observe how the curved surfaces formed without the interference of the liquid’s weight. The experiment, planned over six months by the Budapest team in collaboration with Axiom Space and NASA, required final adjustments in orbit under the supervision of commander Takuya Onishi and the Axiom-4 crew, with Hungarian astronaut Tibor Kapu playing a key role. The results exceeded expectations. The absence of gravity allowed the water to take on configurations impossible on Earth, revealing how minimal surfaces distribute themselves within a volume as unusual as a soft cell.

Such a unique experiment naturally raises the question: how was the soft cell made? Official sources do not specify the exact method used to create the 3D figure. However, this type of prototype is generally produced using 3D printing, as the technique allows highly complex geometries to be reproduced with precision and speed. Moreover, the ISS has been using additive manufacturing for many experiments, both on the ground and in orbit, which makes it highly likely that this project used it as well.

Regarding possible applications, the Mathematical Institute of the University of Oxford emphasizes that these results not only provide a better understanding of the geometry underlying many biological tissues, but also open the door to imagining buildings and structures without angles—a completely new approach to future design.

What do you think of these soft cells? Could they have an impact on the future of space exploration? Let us know in a comment below or on our LinkedIn or Facebook pages! You can read the full press release here to learn more about the announcement. Plus, don’t forget to sign up for our free weekly Newsletter to get the latest 3D printing news straight to your inbox. You can also find all our videos on our YouTube channel. For more 3D printing news in the aerospace and defense sectors, check out our dedicated page HERE.

*Photo Credit: University of Oxford / Budapest University of Technology and Economics