Life on the ISS is never boring and you can do things in microgravity that you could never think of when you are on Earth. You can make floating balls of water for instance simply by squeezing water out of a straw. Astronaut Scott Kelly has shown off something cool that you could never do on Earth, play ping-pong with a floating orb of water.
To do this Kelly uses a pair of hydrophobic paddles. Hydrophobic means that the paddles don’t absorb water. The paddles are laser etched so that the surfaces have arrays of 300-micrometer posts. After the etching process, they are coated with Teflon to keep material from sticking to the surface.
The combination produces what NASA calls a super-hydrophobic surface that is capable of preventing water adhesion in a dynamic process. The larger the drop of water, the easier it is to break up. The smaller the drop, the harder it can be hit.
The ball of water Kelly is playing with in this video is about 4ml. As you can see in the video, it zips back and forth between the paddles losing no visible volume. This could be turned into a very cool drinking game. The video was shot in 4K with one of the RED cameras aboard the ISS.