ESA astronaut Alexander Gerst during his 2018 stay on the International Space Station, with two floating SPHERES robots tethered to a container of liquid, serving to simulate the experience of pulling a derelict satellite out of orbit.
![](https://scx1.b-cdn.net/csz/news/tmb/2020/sloshinginsp.jpg)
Source:
https://phys.org/news/2020-08-image-sloshing-space.html