Form Follows Function: NASA's Zero-Gravity Drinking Cup

This unusual-looking cup was designed by Dr. Mark Weislogel, a former NASA research scientist and expert in fluid dynamics. It has the unusual provenance of having been prototyped not on Earth, but in space.

As the story goes, Dr. Weislogel learned that Donald Pettit, an astronaut doing experiments with fluids on the International Space Station in 2008, was getting sick of drinking out of the pouch-and-straw arrangement astronauts use. Weislogel sent Pettit diagrams of something that could possibly be cobbled together on the ISS, using available materials.

Using Mylar sheeting and tape, Pettit created this primitive “cup.” It’s just a sheet with two opposite edges taped together and an added bottom.

The arrangement uses the principal of “capillary channel flow,” meaning that liquid is naturally drawn towards the crevice-like edge of the cup, and will stay there. Pettit tested it out, and it worked:

With the liquid gathered in the crevice, it’s easy for astronauts to slurp the fluid out.

However, the primitive shape also provides a sharp and unfriendly point right where the drinker’s mouth goes. Back down on Earth Weislogel, who also worked as a professor in the Thermal & Fluid Science Group at Portland State University, refined the design with a more mouth-friendly shape at the drinking edge:

These are now in use on the ISS.

Here’s how the astronauts fill and use them:

As interesting as the shape is, sadly there’s not much application for it on Earth. Nevertheless, a company called Spaceware will sell you an SLA 3D-printed one for $650.

It’s “most definitely not dishwasher safe,” the company writes.

Source: core77