Design and Verification of a Projectile Structure for Main-belt Comets Penetration Exploration

Comparing the isotopic composition of the D/H ratio of the water ice in Main-belt Comets (MBCs) to that of the oceans on the Earth can enhance the understanding of where the water comes from and of how the distribution of the water ices in our early solar system. Herein, a jet penetrator with a turbo-blasting explosion device and a high-precision accelerometer has been proposed to realize a 1m class subsurface detection for China next asteroidal exploration mission. Considering the ruggedness of rubble pile structure in the low-gravity environment, the projectile's posture and its overloads determined by its structure and velocity during the penetration is highly uncertain. By establishing the rubble pile structure penetrating mechanism model, the real-time overloads and posture is analyzed to acquire an optimized projectile structure. Finally, a frozen rubble pile simulant penetrating experiment under gas gun system verified the optimized structure.