The effect of gravity-propelled interplanetary space travel on the exploration of the solar system -- historical survey, 1961 to 2000

摘要

This paper is the third in a series of papers describing the origin of Dr. Michael A. Minovitch's invention of gravity-propelled interplanetary space travel (gravity-assist trajectories), his early work in developing it, and how the various NASA gravity-propelled missions originated from it. The primary aim of the present paper is to describe the effect of the invention and to show that it was not anticipated. This will be achieved by defining the invention as having two primary components, the use of free-fall multiplanetary trajectories and the use of gravitational perturbations, and showing that each component was proved to be impractical prior to the invention. A technical analysis of the invention is also presented to show that it represnted a fundamentally new theory of space travel distinctly different from the classical theory based on reaction propulsion developed by Tsiolkovsky, Goddard, and Oberth. It was Minovitch's theory, a mathematical theory of space travel based on finding a numerical solution for the unsolved Restricted Three-Body Problem for motion through the Solar System, and not the classical theory based on reaction propulsion, an engienering theory, that made it possible to break the high-energy barriers of interplanetary space travel and open the entire Solar System to exploration with instrumented spacecraft.