For application to exploration under the surface of icy objects in the solar system, the penetration of an impact probe into an icy target was experimentally simulated by using the ballistic range. Slender projectiles with a cylindrical body and various nose shapes were tested at the impact velocity 130 -420 m/s. The motion of the penetrator, fragmentation of ice and crater forming were observed by the high-speed camera. It revealed that the crown-shaped ejection was made for a short time after the impact and then the outward normal jet-like stream of ice pieces continued for much longer time. The concave shape of the crater was successfully visualized by pouring the plaster into it. The two-stage structure, the pit and the spall, was clearly confirmed. The rim was not formed around the crater. Observation of the crater surface and the ice around the trace of the penetrator shows that both crushing into smaller ice pieces and recompression into ice blocks are caused by the forward motion of the penetrator. In case of a body with a flow-through duct, ice pieces entering the inlet at the nose tip were ejected from the tail, resulting in relaxation of the impact force. The correlation of the penetration distance and the crater diameter with the impact velocity was investigated.
To realize the penetrator mission for icy objects in the solar system, the penetration dynamics into ice has been experimentally and numerically studied. In the experiments, the ogive/cylinder projectiles of the mass about 2.6 g were tested for the target made from water ice by the ballistic range at the impact velocity 100-350 m/s. The behavior of the projectile and target was observed by the high-speed video camera. The penetration trajectory was visualized by pouring the plaster into the crater. The empirical analysis model to describe the force acting on the body surface has been developed, based on the panel method and the shock wave analogy. It includes two parameters representing the effective speed of sound of crushed ice and the damping of the pitching motion. Fairly good agreement with the experiments was obtained with respect to the stop conditions of the penetrator by setting these parameters appropriately. The computational result assuming a flight model of the mass 14.9 kg and the impact velocity 300 m/s shows that the maximum deceleration G is in the same order as that for the lunar penetrator.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.