Impact Frequency Estimate of Micron-sized Meteoroids and Debris on Tanpopo Capture Panels on the ISS

This study is a part of ‘Tanpopo’ mission, which is to be mounted on the Exposure Facility of the Japanese “Kibo” Module of the International Space Station. The purpose of this study is to comparing the impact frequency that is predicted from the debris environment model and the impact craters on the exposed instrument. There are two approaches to achieve this plan. The first is to predict the impact frequency of the micron-sized debris onto the Tanpopo capture panels which is exposed to space. The second is to establish methods for calculating key parameters in relation to impacting debris particles from excavated craters on the capture panel material. The debris impact frequency on the capture panels was predicted using the impact-risk analysis tool. It was found that impact of particles of 10 μm or less in diameter was expected on the panels. Additionally, the relationship between the debris impact energy and crater was also derived by hypervelocity impact experiments. It was found that regardless of the projectile materials and impact speed, the relationship between the impact energy and the crater volume is nearly proportional.