Data from a laboratory simulation of current collection by a highly bi
ased body in a spacecraft wake are presented. Ion collection from the
plasma stream is investigated for both axisymmetric and nonaxisymmetri
c geometries. Spatially resolved current collection data, obtained by
using a segmented collector, are presented for the first time. A thres
hold potential for the onset of current collection exists; this thresh
old depends strongly on the geometry of the problem and is related dir
ectly to the details of the trajectories of the collected ions. Result
s from an approximate numerical model of the laboratory experiment as
well as the predictions of a simplified analysis are given. The agreem
ent of the numerical solution with the experimental data is good.