The communication `blackout' in the reentry stage of a space mission is a serious threat to the reentry vehicle. The terahertz (THz) technology is supposed to be a potential solution to the `blackout' problem in the recent decade. In the present paper, the relation between the THz waves' transmission in the reentry plasma sheath and the angle of attack (AOA) of the vehicle is investigated. A three dimensional numerical model is introduced in order to obtain the plasma parameters in the reentry plasma sheaths. The computation results show that both the electron density and the electron collision frequency vary with the AOA. As results, the transmission rates for the THz waves vary with the AOA as well. According to the analysis, microwave communication system is very likely to suffer from the `blackout' in the reentry stage. The THz scheme is an effective solution. The fluctuation of AOA may weaken the signal strength received by the onboard antenna. On the other hand, keeping the AOA in an appropriate range is helpful for strengthening the received THz signals. Also, the AOA for the best THz communication quality is obtained according to the analysis.
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