Modeling of copper needle clusters from the West Ford Dipole experiments

Clusters consisting of short pieces of thin copper wires have been released during experiments within the West Ford Project in the early sixties on orbits near 3,600 km altitude. The wires should serve as dipole antennas and are also designated as "West Ford Needles". This paper describes the modeling approach for the release of clusters and considers objects with area-to-mass ratios from about 1 m²/kg to 5 m²/kg. The release events are simulated, and the results of a propagation to generate an object population at a reference epoch are presented. The clusters have average geometric diameters between several 100 mum and some millimeters. The contribution to the space debris population in this size range is relatively small.