Spacecraft Entry and Landing in Planetary Atmospheres

Abstract

This chapter describes the spacecraft entry and landing in planetary atmospheres. The development of long-range ballistic missiles has required that concentrated attention be focused on many challenging technical problems associated with atmospheric entry. With appropriate adaptations, these missiles have been used as space carrier vehicles, making possible the realization of many astronautical missions. Attention has consequently been given to the entry problems involved in recovery of vehicles from near-earth orbits and from lunar and planetary trajectories. The frame of reference to be used for the postulation of a nonrotating spherical planet is an inertial frame with its origin at the point of intersection of the planet's surface with the radius vector from its center to the chosen initial point of the entry trajectory. The coordinate system trajectory lies in the x–z plane. As a space vehicle decelerates during its passage through a planetary atmosphere, its kinetic energy is dissipated as heat energy. Formulation of the heat transfer problem requires knowledge of the flow regimes to be encountered which, in brief, are free molecular flow, transitional flow, and continuum flow.