Dynamic Modelling Transformations for the Low Earth Orbit Satellite Particulate Environment

Abstract

A simple dynamic model to investigate the relative fluxes and particle velocities on a spacecraft’s different faces is presented. The results for LDEF are consistent with a predominantly interplanetary origin for the larger particulates, but a sizable population of orbital particles with sizes capable of penetrating foils of thickness <30μm. Data from experiments over the last 30 years do not show the rise in flux expected if these were space debris. The possibility of a population of natural orbital particulates awaits confirmation from chemical residue analysis.

Particulate Detection in the Near Earth Space Environment Aboard the Long Duration Exposure Facility Ldef: Cosmic or Terrestrial?

“…Arguing against this source being space debris, the temporal behaviour of the near Earth satellite flux is seen to be remarkably stable over the development of a growing space population (McDonnell et al, 1991). If this micron dimensioned particulate flux is supposed to be debris related, as concluded by Laurance and Brownlee's association of residual elemental comparisons with typical spacecraft material, then we could be forced to conclude that there was as much space debris in the early 1960s as in 1984, despite the linear growth of space launches and the orbital satellite population.…”

“…Relationships in this sensitivity enhancement have been established (McDonnell et al, 1991). Since the West face flux distribution can be assumed to be the result of non-Earth bound particles, a prediction of the interplanetary flux as encountered by any other LDEF face can be achieved by dynamical modelling.…”

“…It could call for higher particle velocities at these masses, which would be closer to interplanetary approach velocities deduced from meteor studies. Further aspects are developed in an accompanying paper (McDonnell et al, 1991).…”