Effect of Plasma on Electromagnetic Wave Propagation and THz Communications for Reentry Flight

The spacecraft will experience the well-known “blackout” problem when it re-enters into the Earth’s atmosphere, which results in communication failures between the spacecraft and the ground control center. It is important to study the effect of the plasma on electromagnetic wave (EMW) propagation. The properties of EMW propagation in plasma based on theoretical analysis have been studied in this paper, which indicate that communications using terahertz (THz) wave is an alternative method for solving the blackout problem. The properties of 0.22 THz EMW propagation in plasma have been studied experimentally with shock tube, and the experimental results are in good agreement with the theoretical ones. Both the theoretical and experimental results indicate that communications using THz wave is an alternative and effective way to solve the blackout problem.