  We introduce here our new approach to modeling particle cloud evolution off
surface of small bodies (asteroids and comets), following the evolution of
ejected particles requires dealing with various time and spatial scales, in an
efficient, accurate and modular way. In order to improve computational
efficiency and accuracy of such calculations, we created an N-body modeling
package as an extension to the increasingly popular orbital dynamics N-body
integrator Rebound. Our code is currently a stand-alone variant of the Rebound
code and is aimed at advancing a comprehensive understanding of individual
particle trajectories, external forcing, and interactions, at the scale which
is otherwise overlooked by other modeling approaches. The package we developed
-- Rebound Ejecta Dynamics (RED) -- is a Python-based implementation with no
additional dependencies. It incorporates several major mechanisms that affect
the evolution of particles in low-gravity environments and enables a more
straightforward simulation of combined effects. We include variable size and
velocity distributions, solar radiation pressure, ellipsoidal gravitational
potential, binary or triple asteroid systems, and particle-particle
interactions. In this paper, we present a sample of the RED package
capabilities. These are applied to a small asteroid binary system
(characterized following the Didymos/Dimorphos system, which is the target for
NASA's Double Asteroid Redirection Test mission)
