Microgravity Experiment to Measure the Speed of Sound Inside Simulated Asteroid Regolith in the ISS Environment

In impact threat assessments of planetary defense options, the aim is to understand how seismic waves travel through the debris, either modifying its shape or its surface. Seismic disturbances can destabilize loose material resting on the slope, causing downward flows. With the Microgravity Experiment for Asteroid Regolith Sound Velocity (MESSAR), it is proposed to measure the sound velocity within the simulated asteroid regolith in the microgravity environment of the International Space Station (ISS). The payload contains several granular samples of simulated asteroid regolith that will be used to measure the influence of grain size and confining pressure on the wave travel speed.