Flexible Diggers for Interacting with Granular Surfaces in Low Gravity

For spacecraft visiting rubble pile asteroids it is important to safely interact with the granular materials at the surface of these objects. We propose the use of flexible probes for digging into a granular material under conditions of low gravity. In our experiments we show that low-speed interactions reduce the effects of shock wave creation and observe that more flexible diggers allow the grains to rearrange and therefore lower the peak loads experienced.

Jonathan Kollmer received his Ph.D. in Physics from the Friedrich-Alexander-Universität Erlangen-Nürnberg in 2015. His thesis topic was 'Harmonic, Subharmonic and Quasi-Periodic Flows in Granular Matter' with a focus on granular dynamics in microgravity. After completing his Ph.D., he was a Postdoctoral Scholar at the North Carolina State University, where he studied photo-elastic force measurements and application of network theory to granular media. In 2018 he returned to Germany to work towards habilitation at the University of Duisburg-Essen. Here he applies his expertise in granular materials to experimentally research early planet formation processes as well as natural and robotic interaction with asteroid surfaces.