Communication blackout and aerodynamic heating reduction via air film for hypersonic spacecraft

This study investigates the use of gas jet injection to mitigate both radio frequency blackouts and aerodynamic heating experienced by spacecraft during atmospheric reentry. The key concept behind this approach is that the injected gas forms a thin air film layer around the spacecraft. This air film acts as an insulating layer, reducing heat transfer and creating a low-plasma region, allowing electromagnetic waves to propagate through the surrounding plasma of the spacecraft. To assess the effectiveness of this method, a parametric study was conducted using computational fluid dynamics simulations on an actual reentry vehicle. The results indicate that gas injection from the vehicle’s leading edge provides a localized reduction in heat flux, while injection from the sidewall forms a more extensive protective air film along the vehicle surface, significantly reducing heat flux over a broader area. Furthermore, the formation of the air film creates a low-plasma region, facilitating the transmission of electromagnetic waves. These computational findings demonstrate that simultaneous mitigation of both heat flux and radio frequency blackouts is achievable under realistic atmospheric reentry conditions. This air film effect presents a promising solution to these two major challenges, potentially enhancing the flexibility of space transfer missions.