Momentum Predictability and Heat Accumulation in Laser-based Space Debris Removal

Kurzfassung

Small-sized space debris objects pose a challenging threat for aerospace security: Within a size range of 1 to 10 centimeters they are still large enough to cause severe damage to space assets but, moreover, they are almost too small to be detected and monitored. Recent progresses in laser-based debris monitoring yield promising results in detection and tracking of even small-sized debris objects and enable for the short-term solution of obstacle avoidance maneuvers. For the long run, however, it has to be analyzed whether and how the usage of high energy lasers can provide for a reliable solution of the space debris problem in the abovementioned particle size range. In our simulations we explore both potential and limitations of laser-ablative momentum generation, in particular with respect to the predictability of its magnitude and direction as well as to the accumulation of residual heat from the ablation process. For this purpose, we use Monte Carlo simulations with a variety of debris target geometries in order to analyze how restrictions in laser pointing accuracy as well as random target orientation affect the predictability of laser-ablative momentum generation. Moreover, pulse number restrictions are discussed in order to avoid target melting and its compactification. A database on laser-matter interaction is established for various materials and laser parameters enabling us to account for the local fluence distribution on the target surface obtained by raytracing with respect to the laser beam profile. Accordingly, main similarities and differences between short-pulse and ultrashort-pulse laser ablation are highlighted and discussed with respect to their implications for debris removal.