Propagation Path of Radio Waves in Nonequilibrium Reentry Plasma Around a Nanosatellite With an Inflatable Aeroshell

A communication blackout is one of the major problems that occurs during the reentry of a satellite into the Earth’s atmosphere, which is caused by the reentry plasma blocking electromagnetic waves near the satellite for telecommunication. Moreover, it prevents tracking and data transmission, resulting in inaccurate prediction of landing sites and data loss. Therefore, there is a necessity to evaluate the propagation of electromagnetic waves in the reentry plasma and to mitigate the communication blackout. An inflatable aeroshell technology with lightweight and large-area features enables aerodynamic drag at high altitudes to reduce aerodynamic heating and to mitigate communication blackouts. Thus, a nanosatellite mission using such an inflatable aeroshell has been proposed. For the purpose of telecommunication possibilities during the reentry in future nanosatellite missions, a detailed investigation of communication blackout mitigation by inflatable aeroshell is required. In the present article, the plasma flow and electromagnetic wave propagation near the nanosatellite during atmospheric reentry were revealed by using a computational science approach. A low-temperature and low-density wake is formed behind the nanosatellite. Moreover, an electromagnetic wave propagation path is formed in the wake, indicating that this path is maintained during the reentry, and no communication blackout occurs when using the deployable nanosatellite.