With full color illustrations. This TR is actually a textbook on atmospheric entry for several classes at AFIT. It teaches from an analytical perspective, with finding closed-form solutions being the preferred approach. The over-arching goal is to instill and understand how families of solutions behave as well as the general trends, trade-offs, and the nature of atmospheric entry before picking point designs to study in detail. By thoroughly understanding the classic analytic analyses first, we can better use the computer to solve the hard problems. The book's approach is to use easily visualized variables to solve the analytical problems first and keep them (more-or-less) consistent as we move to the computer. This is a back to the basics approach for a new generation of students who've become more comfortable with numerical solutions than analytical ones. The pages are loaded with equations because the details of many of the derivations are included. This book pulls together many classical analyses and presents them in a consistent notation for the first time. It provides a convenient starting point for an analytical understanding of atmospheric entry, with plenty of references to those original works. It ties together results that were originally published years apart by different authors. And, peppered throughout, you'll find some new approaches and results.