2023 · INTERNATIONAL JOURNAL OF IMPACT ENGINEERING

Momentum enhancement from 3-cm-diameter aluminum sphere impacts into iron and rock at 5 km/s

Walker, James D., Chocron, Sidney, Grosch, Donald J., Marchi, Simone, Alexander, Amanda M.

Journal
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
Année
2023
Volume
180
Article
104694
Mois
OCT
DOI
10.1016/j.ijimpeng.2023.104694

Abstract

Utilizing a large two-stage light gas gun and a large pendulum assembly, experiments were performed to measure the momentum enhancement (or increase in momentum transfer due to the ejecta) of an ARMCO iron target, two large hematite rock targets, a target of stones held by concrete, and a concrete block target. The choice of iron and iron rich materials was motivated by interest in the asteroid Psyche and the planned upcoming mission. The target comprised of a collection of stones, to mimic a rubble pile asteroid, was to provide insight into the Double Asteroid Redirection Test (DART) impact. The role of impactor size is important, and these tests were performed at a large scale, with 3-cm-diameter aluminum spheres as the impactor. Save for the concrete block, these impacts were in the vicinity of 5 km/s. There is a distinct difference in the amount of momentum enhancement (measured by & beta;) that occurs with ductile metals vs. brittle materials and this fact shows in these impacts. The momentum enhancement with a relatively brittle aluminum falls in between the two extremes of rock and iron. Computations were performed to compare with the ARMCO iron impacts. Data at a large scale is desirable to quantify momentum enhancement in the context of hypervelocity impactors deflecting celestial bodies such as asteroids or comet nuclei.

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