Speed affects the recirculation zone and wake of blunt bodies like the Apollo during reentry, with Mach number and Reynolds number being critical parameters. Subsonic and transonic speeds tend to increase the length of the recirculation zone, while supersonic and hypersonic speeds generally decrease it. The discussion highlights the niche nature of this topic, suggesting that detailed answers are often found in specialized research rather than general forums. Invoking concepts like shock angles and viscous phenomena, the conversation emphasizes the importance of geometry and flow conditions in understanding these dynamics. Further independent research, particularly through academic papers, is recommended for deeper insights.