New tools are necessary to deal with more than hundred thousands of space debris, thus our aim is to develop software able to propagate numerous trajectories and manage collisions or fragmentations. Specifically in low orbits Earth, gravity and atmospheric drag are the two main forces that affect the dynamics of the artificial satellites or space debris. NIMASTEP, the local orbit propagator, initially designed for high altitudes, has been adapted to low altitude orbits. To study the future debris environment, we propose a suitable model of space weather and we compare three different atmospheric density models (Jacchia-Bowman 2008, DTM-2013, and TD-88) able to propagate with accuracy and efficiency a large population of space debris on long time scales. We compare the results in different altitudes and during the reentry regime; we show, with a ballistic coefficient constant, a trend to underestimate or overestimate the decrease of the semi-major axis, specifically during the periods of high solar activity. We parallelize our software and use the calculation power of a computing cluster, we propagate a huge cloud of debris and we show that its global evolution is in agreement with the observations on several years.