**5. Conclusion**

The aerodynamic characteristics of the reentry capsules are studied experimentally employing the shock tube, the high enthalpy tunnel, wind-tunnel, and free-flight testing. The experimental set up has to design to meet the specific requirements and conditions for the reentry probes. The post flights test data are available for many reentry modules. The flow fields over many reentry modules are generated using computational fluid dynamics for various test conditions. The computational fluid dynamics can be used to analyze and understand the complex flow field features in the wake region of the modules. Numerical simulation can be used to get aerodynamic characteristics, wall heat flux, and stability margin for the optimization of the trajectory of the capsules.
