Nicholas L. Johnson

TL;DR: In this paper, the authors compare the new breakup model to the old breakup model in detail, including the size distributions for explosions and collisions, the area-to-mass and impact velocity assignments and distributions, and the delta-velocity distributions.

TL;DR: The LEGEND (LEO-to-GEO Environment Debris model) is a high-fidelity three-dimensional physical model developed by the U.S. National Aeronautics and Space Administration (NASA) that is capable of simulating the historical environment and the evolution of future debris populations as discussed by the authors.

TL;DR: In this article, a removal criterion based upon mass and collision probability is developed to rank objects at the beginning of each projection year, with removal rates ranging from 2 to 20 objects per year, starting in the year 2020.

TL;DR: In this article, a new study has been conducted in the Orbital Debris Program Office at the NASA Lyndon B. Johnson Space Center, using higher fidelity models to evaluate the current debris environment.

TL;DR: The causes of on-orbit satellite fragmentation are varied and may be intentional or accidental as discussed by the authors, and the cause of many fragmentations remains unknown, however, man is directly responsible for the vast majority of artificial debris polluting the near-Earth space environment.