Speaker
Description
The dust (up to mm size) flux in Low Earth Orbit (LEO) is a combination of natural cosmic dust and anthropogenic debris from spacecraft. As well as the threat of impacts on operational satellites from other satellites and defunct satellites, old upper stages etc., there is also a serious impact threat from such mm sized objects [1]. The contribution to the flux from space debris is held to be about to rapidly increase, yet there is a lack of data in this size regime [2]. It cannot be observed from the ground, so previous estimates were mostly derived by studying surfaces of spacecraft materials retrieved from LEO, searching for craters produced when dust impacted. But such retrievals are now rare. Hence, in-situ measurements are now required. The urgent need for new measurements and how they will require dedicated missions will be discussed.
Given current flux estimates, large detector surface areas will be required to produce annual estimates of the flux at the mm size scale, which will permit monitoring of the environment to see if it is degrading with time. Without the data from such missions, no informed debate on the hazard can be undertaken, and decisions will be made with minimal real input. Therefore new, in-situ, real-time measurements of the dust flux in LEO must be an important part of any strategy for sustainable space.
[1] Cornwell et al., Advances in Space Research, in press. 2025. https://doi.org/10.1016/j.asr.2024.06.058. [2] Wozniakiewicz and Burchell, A&G, 60(3), 38–42, 2019, https://doi.org/10.1093/astrogeo/atz150
