Preliminary Debris Risk Analysis for Mega-Constellation Architectures After Orbit-Raising Fragmentation Event

Abstract

This paper presents a theoretical examination of the potential debris conjunction dangers faced by mega-constellations in both low Earth orbit (LEO) and medium Earth orbit (MEO). The analysis focuses on the risks posed by debris fields created by breakups occurring during an orbit-raising maneuver for vehicle replacement and/or capability reconstitution, using current telecommunications mega-constellations, such as Starlink and OneWeb, as examples. The mega-constellation designs consist of 750 and 150 satellites arranged using the Walker-Delta design for the LEO and MEO cases, respectively. The research employs physics-based orbital propagation and Monte Carlo simulations to evaluate the potential consequences of a single satellite breakup during orbit raising. The results of the simulations are used to calculate the probability of catastrophic collision and compare the debris risk between the LEO and MEO mega-constellations, with a bimodality analysis conducted for the MEO constellation. Monte Carlo analysis indicates that the LEO mega-constellation features the highest percentage of potential catastrophic collisions between debris fragments and the mega-constellation. Specifically, satellite breakup events starting within an altitude range of 100–199 km below the LEO mega-constellation, or approximately at the midpoint of a Hohmann transfer from a 300-km parking orbit, pose the greatest risk to the constellation.