A tethered plate satellite as a sweeper of small space debris

Removing space debris is an urgent task to ensure sustainable space activity. Towards this end, we propose herein a tethered plate satellite that can remove many items of small space debris successively by collisions alone without capturing them or performing major orbital manoeuvres. The strategy involves a tethered plate that moves more slowly than the space debris at the same altitude so that the speed difference in the collision causes re-entry of the space debris. Numerical verification using an on-orbit object database indicates that, for the requisite number of collisions, this strategy would require a reasonable amount of orbital manoeuvres. The results indicate that six such spacecraft operating for one decade would suffice to reduce the amount of removable space debris in a certain altitude range by 96.10%. Based on these results, a mission concept is proposed in which debris-removal systems would remove almost all the removable space debris in a given altitude range, thereby allowing for the operation of large satellite constellations.