Introduction to Space Dynamics
By William Tyrrell Thomson
When this little book came out, in the early sixties, it created quite an impact. For one thing, it marks the transition from the "old astrodynamics" to the "new". The term "astrodynamics" is attributed to the late Samuel Herrick, and was coined in the forties or early fifties. Prior to sputnik, astrodynamics was heavily centered on determining the orbits of comets and asteroids from optical observations. When artificial satellites became imminent, the emphasis shifted to determining physical constants (e.g., figure of the earth) from satellite tracking data.
"Introduction to Space Dynamics" represents a new departure. First, it places considerable emphasis on launch vehicle (rocket) performance, including some optimization analysis based on the calculus of variations. The older texts tended to completely ignore this topic (possibly because much was classified). Also, except for Lawden's monograph, many of the papers on optimized launch vehicle performance were difficult to obtain - and generally difficult to read. Second, Thomson inserts considerable material on gyroscopic motion, stabilized platforms, and inertial navigation. This represents a transition away from the optical-tracking-orientation of earlier texts. Thomson's book also enjoys the benefit of more modern notation, and uses vector and matrix notation throughout.
A curious included topic -- to which I was first introduced by this very book -- is "jet damping." The jet damping effect tends to dampen-out any angular motion of a rocket during thrusting periods. However, the effect is small to the point of usually being negligible. (Witness the notorious instability of rockets, particularly unguided ones.) Considering how much material Thomson devotes to this very specialized topic, one gets the impression that Thomson himself must have performed considerable research on this, and was determined to pass his knowledge on.
It is almost inevitable to compare this book with Herrick's "Astrodynamics", which came out some ten years after "Introduction to Space Dynamics." While Herrick's book is without question beautifully written and very comprehensive, it is basically backward-looking. Thomson's book, on the other hand, was very progressive for its time. Consequently, Thomson's book was very influential; Harrick's book was something of a curiosity, and almost certainly a disappointment for its author.
Despite the forty-some years since its debut, "Introduction to Space Dynamics" is still valuable, and should be read by everyone seriously interested in astrodynamics.