Neglecting small fragments in space debris models can lead to a significant underestimation of the collision risk for operational satellites. The evaluation of their individual effect is however prohibitive from a computational point of view. Probabilistic methods provide a more efficient alternative to this problem.
The new paper by Lorenzo Giudici, Juan Luis Gonzalo, and Camilla Colombo proposes a novel method for the estimation of the collision probability for orbiting spacecraft from the density of an evolving fragments cloud, applicable to any orbital regime and conjunction geometry. Leveraging on its probabilistic nature, it allows the modelling of the risk posed by fragments in the centimetre and millimetre range.
The paper is available here.