Mitigation of small space debris

Abstract

Space debris fragments smaller than 10 cm cannot be tracked from Earth and are generally neglected in conjunction and risk analyses because of this. However, these fragments pose a great threat, as they can lead to collisions. Currently, the threat that space debris poses on the space environment is getting larger, so methods to mitigate said debris need to be explored. The technique that was studied here, consisted of a passive spacecraft with a circular cross-sectional surface of a material, such as aerogel or foam, with the ability to decelerate and catch the debris fragments encountered. Given this choice, a capture analysis was carried out for such a potential technique. It was concluded, that the most favorable orbital settings for such a method, would be in the case of an explosion of an active or defunct spacecraft, as a direct reaction device. This scenario was then simulated using the orbital parameters of the Kosmos 1408 anti-satellite missile test. The results showed that for a spacecraft with a collector radius of 20 meters, 2 to 3% of the newly created fragments were caught, whereas, for a larger spacecraft with a radius of 100 meters, that number increased to up to 12%. The ideal deployment time for a spacecraft of 20 meters radius was found to be 12 hours after the fragmentation, whereas for 100 meters it was 6 hours. It was found that the capability of such a method is highly dependent on the catcher size, whereas deployment time has a smaller impact. Moreover, it was concluded that the performance of this technique is very sensitive to injection inaccuracies, as the number of fragments caught would be close to zero.