Solid-rocket-motor contribution to large-particle orbital debris population

Abstract

Observations of solid-rocket-motor static firings indicate that these motors contribute to the centimeter-sized orbital debris population when they are used as launch vehicles. An analytic solution for the orbital distribution of this ablative debris from on-orbit solid-rocket-motor firings is presented and applied to a data set containing a large fraction of such firings in Earth orbit during the 1980s. Assuming 400 ablative objects are released per burn, it is found for altitudes above about 500 km that their spatial density is negligible in comparison with predicted 1-cm densities from other sources for the year 1990. Ablative-debris densities exceed predictions for other sources below about 250 km, but these densities are small. In the planned altitude range for the International Space Station (about 400 km), our results suggest that ablative particles pose about 10% as great a hazard as debris from other sources. However, these results are preliminary and should be updated as more complete data become available regarding the number of particles emitted per firing and historical solid-rocket-motor launches.