The mechanics of similarity encompasses the analysis of dimensions, performed by various procedures, the gasdynamic similarity and the model technology. The analysis of dimensions delivers the dimensionless numbers by which specific physical challenges can be described with a reduced number of variables. Thereby the assessment of physical problems is facilitated. For fluid dynamics and all sorts of heat transfer the discipline of the mechanics of similarity was so important in the past, that the historical background is highlighted of all the persons who have contributed to the development of this discipline. The goal of the classical gasdynamic similarity was to find rules, which enables the aerodynamic engineer to perform transformations from existing flow fields to others, which meet geometrical and other specific flow field parameters. Most of these rules and findings do no longer play a role today, because a lot of potent experimental and theoretical/numerical methods are now available. This problem is addressed in the book. A recent investigation regarding the longitudinal aerodynamics of space vehicles has revealed, that there exist other astonishing similarities for hypersonic and supersonic flight Mach numbers. It seems, that obviously most of the longitudinal aerodynamics is independent from the geometrical configurations of the space vehicle considered, if a simple transformation is applied. A section of this book is devoted to these new findings.

The mechanics of similarity encompasses the analysis of dimensions, performed by various procedures, the gasdynamic similarity and the model technology. The analysis of dimensions delivers the dimensionless numbers by which specific physical challenges can be described with a reduced number of variables. Thereby the assessment of physical problems is facilitated. For fluid dynamics and all sorts of heat transfer the discipline of the mechanics of similarity was so important in the past, that the historical background is highlighted of all the persons who have contributed to the development of this discipline. The goal of the classical gasdynamic similarity was to find rules, which enables the aerodynamic engineer to perform transformations from existing flow fields to others, which meet geometrical and other specific flow field parameters. Most of these rules and findings do no longer play a role today, because a lot of potent experimental and theoretical/numerical methods are now available. This problem is addressed in the book. A recent investigation regarding the longitudinal aerodynamics of space vehicles has revealed, that there exist other astonishing similarities for hypersonic and supersonic flight Mach numbers. It seems, that obviously most of the longitudinal aerodynamics is independent from the geometrical configurations of the space vehicle considered, if a simple transformation is applied. A section of this book is devoted to these new findings.

The capacity and quality of the atmospheric flight performance of space flight vehicles is characterized by their aerodynamic data bases. A complete aerodynamic data base would encompass the coefficients of the static longitudinal and lateral motions and the related dynamic coefficients. In this book the aerodynamics of 27 vehicles are considered. Only a few of them did really fly. Therefore the aerodynamic data bases are often not complete, in particular when the projects or programs were more or less abruptly stopped, often due to political decisions. Configurational design studies or the development of demonstrators usually happen with reduced or incomplete aerodynamic data sets. Therefore some data sets base just on the application of one of the following tools: semi-empirical design methods, wind tunnel tests, numerical simulations. In so far a high percentage of the data presented is incomplete and would have to be verified. Flight mechanics needs the aerodynamic coefficients as function of a lot of variables. The allocation of the aerodynamic coefficients for a particular flight operation at a specific trajectory point is conducted by an aerodynamic model. The establishment of such models is described in this book. This book is written for graduate and doctoral students to give them insight into the aerodynamics of the various flight configurations. Further for design and development engineers in industry and at research institutes (including universities) searching for an appropriate vehicle shape, as well as for non-specialists, who may be interested in this subject. The book will be helpful, too, in the case that system studies require in their concept phases the selection of suitable vehicle shapes.

Hypersonic ?ight and aerothermodynamics are fascinating topics. Design problems and aerothermodynamic phenomena are partly very di?erent for the various kinds of hypersonic ?ight vehicles. These are-and will be in the future-winged and non-winged re-entry vehicles as well as airbreathing cruise and acceleration and also ascent and re-entry vehicles. Both authors of the book worked for almost four decades in hypersonics: at the German aerospace research establishment (DVL/DFVLR, now DLR) to the end of the 1970s, then in industry (MBB/Dasa, now EADS). They were involved in many major technology programs and projects. First, in the early 1970s, the German ART program (Association for Re-Entry Te- nologies), and, in the 1980s, the European (ESA) HERMES project and the .. German Hypersonics Technology (SANGER) program. Then followed, in the 1990s, the Future European Space Transportation Investigations program (FESTIP), the Manned Space Transportationprogram(MSTP) with the - mosphericRe-EntryDemonstrator(ARD), theX-CRVProjectwiththe X-38 vehicle and, later, the German technology programs TETRA (Technologies for Future Space Transportation Systems), ASTRA (Selected Systems and Technologies for Future Space Transportation Systems Applications), and IMENS (Integrated Multidisciplinary Design of Hot Structures for Space - hicles). Research in the 1960s and 1970s placed great emphasis on low-density ?ows, high temperature real gas e?ects in ground-simulation facilities and, already, on discrete numerical computation methods. After the ?rst ?ights of the Space Shuttle Orbiter with its generally very good aerodynamic p- formance, interest in low-density problems diminished.

Themechanicsofspace?ightisan olddiscipline.Itstopicoriginallywasthemotion of planets, moons and other celestial bodies in gravitational ?elds. Kepler's (1571 - 1630) observations and measurements have led to probably the ?rst mathematical description of planet's motion. Newton (1642 - 1727) gave then, with the devel- ment of his principles of mechanics, the physical explanation of these motions. Since then man has started in the second half of the 20th centuryto capture ph- ically the Space in the sense that he did develop arti?cial celestial bodies, which he brought into Earth's orbits, like satellites or space stations, or which he did send to planets or moons of our planetary system, like probes, or by which p- ple were brought to the moon and back, like capsules. Further he developed an advanced space transportation system, the U.S. Space Shuttle Orbiter, which is the only winged space vehicle ever in operation. In the last two and a half decades there were several activities in the world in order to succeed the U.S. Orbiter, like the HERMES project in Europe, the HOPE project in Japan, the X-33, X-34 and X-37 studies and demonstrators in the United States and the joint U.S. - European project X-38. However, all these projects were cancelled. The motion of these vehicles can be described by Newton's equation of motion.

The capacity and quality of the atmospheric flight performance of space flight vehicles is characterized by their aerodynamic data bases. A complete aerodynamic data base would encompass the coefficients of the static longitudinal and lateral motions and the related dynamic coefficients.

In this book the aerodynamics of 27 vehicles are considered. Only a few of them did really fly. Therefore the aerodynamic data bases are often not complete, in particular when the projects or programs were more or less abruptly stopped, often due to political decisions. Configurational design studies or the development of demonstrators
usually happen with reduced or incomplete aerodynamic data sets. Therefore some data sets base just on the application of one of the following tools: semi-empirical design methods, wind tunnel tests, numerical simulations. In so far a high percentage of the data presented is incomplete and would have to be verified.

Flight mechanics needs the aerodynamic coefficients as function of a lot of variables. The allocation of the aerodynamic coefficients for a particular flight operation at a specific trajectory point is conducted by an aerodynamic model. The establishment of such models is described in this book.

This book is written for graduate and doctoral students to give them insight into the aerodynamics of the various flight configurations. Further for design and development engineers in industry and at research institutes (including universities) searching for an appropriate vehicle shape, as well as for non-specialists, who may be interested in
this subject. The book will be helpful, too, in the case that system studies require in their concept phases the selection of suitable vehicle shapes.