This project aimed to develop and verify a numerical model of a brush. This model is meant to aid the study and design of brushes in Active Space Debris Capture. The model is based on the Discrete Element Method and uses the YADE software package to construct the brush model. This model simulates the dynamics of a bristle, their collisions among themselves and other bodies. The behaviour of the brush predicted by the DEM model was compared to observations recorded from three different experiments. The first test compared the dynamic behaviour of bristle, the second focused on the brush's static behaviour, and the final test studied its dynamic behaviour. The experiment observations fall within the behaviour predicted by the model, within the limits of the experiment.