Water Droplet Science with Astronaut Don Pettit on the ISS

NASA astronaut Don Pettit demonstrates electrostatic forces using charged water droplets and a knitting needle made of Teflon. This series of overlapping frames from Feb. 19, 2025, displays the unique attraction-repulsion properties of Teflon and charged droplets, similar to how charged particles from the Sun behave when they come in contact with Earth’s magnetic field. Highly energetic particles from space that collide with atoms and molecules in the atmosphere create the aurora borealis.

Knitting needles made of different materials arrived aboard station as personal crew items. Pettit electrically charged the needles by rubbing each one with paper. Then, he released charged water from a Teflon syringe and observed the water droplets orbit the knitting needle, demonstrating electrostatic orbits in microgravity. The study was later repeated in a simulation that included atmospheric drag, and the 3D motion accurately matched the orbits seen in the space station demonstration. These observations could be analogous to the behavior of charged particles in Earth’s magnetic field and prove useful in designing future spacecraft systems.

For more information visit
https://www.nasa.gov/image-article/water-droplet-science/
https://www.youtube.com/watch?v=qHrBhgwq__Q
https://www.youtube.com/watch?v=pQPosDg1OUU