Thermal protection systems in spacecraft re-entry - A brief overview

Space exploration missions include earth atmospheric entries at high velocities or into an atmosphere of other planets such as Jupiter or Titan with highly radiative constituents. Amongst all the re-entry requirements, protection of the vehicle from the extreme heat generated remains as the single most important consideration. Various mission requirements have necessitated different re-entry strategies and heat protection systems. Traditionally, heat protection methods have included heat sink, ablation and radiative cooling. In recent times, innovative advanced flow control methodologies are also being explored to provide effective thermal protection. The present paper reviews some of the modes employed in atmospheric re-entry before discussing the thermal protection systems.