An unexpected space debris population with the unique property of a very high area-to-mass ratio (HAMR) was detected in 2004 by Schildknecht and colleagues. Ever since, attempts have been made to investigate the dynamical properties of these objects further. Their orbits are heavily perturbed by the effect of direct radiation pressure, and unknown attitude motion complicates orbit prediction. The area-to-mass ratio of the objects seems to be unstable over time. Only sparse optical data are available for these objects in drift orbits.
This paper makes use of optical observations of five HAMR objects, observed over several years, and investigates the variation of their area-to-mass ratio and orbital parameters. A normalized orbit determination setup is established and validated with two low- and two high-area-to-mass-ratio-objects, to ensure that comparable orbits over longer time spans are determined even with sparse optical data.