NewSpace and its implications for space debris models

Abstract

Until two decades ago, the dominance of the space industry by national governments shaped the key characteristics of the spacecraft population and hence the space debris models used to anticipate future orbital populations. The rise of `NewSpace’ with the growth of private sector involvement has brought innovations, disrupting the status quo and changing to the physical characteristics and mission orbits of commercial spacecraft. Analysis of shifts in mass and launch traffic for spacecraft launched between 1980 and 2019 (source: ESA's DISCOS database) suggests significant impacts for debris modelling. Results emphasised the ongoing change towards a more commercially focused space sector. 742 spacecraft were launched in the 1980s, of which 34 were labelled as commercial. By contrast, there were 1292 commercial missions out of 2325 launched in the 2010s - an increase from 4.6% to 55.6%. These increases correlate with a rise in the number of different organisations operating spacecraft and a clear trend can be seen towards smaller, lower mass spacecraft. This is likely to alter the distributions of fragments generated in collisions compared with the distributions obtained from empirical methods, such as the NASA Standard Breakup model, derived from the fragmentation of larger spacecraft in the 600-1,000 kg range. A study of observed breakup events indicates that the NASA Standard Breakup Model over-estimates the number of large debris released during fragmentations due to collisions or explosion of satellites while also under-estimating the number of small debris. It is believed that this will have a significant impact on the outcomes of simulations of the future debris environment where these fragmentation modes are expected to dominate the generation of new debris over the propulsion based explosions which have been historically prevalent.