TABLE OF CONTENTS Orbital rendezvous and docking operations are essential to the execution of many missions, particularly those involving manned spaceflight. First proven during the manned Gemini flights of 1965 and 1966, rendezvous and docking was a required technique for the Apollo lunar landing missions and the Skylab program. It is essential for space shuttle missions involving satellite retrieval, inspection, or repair as well as assembly and support missions to the International Space Station. Unmanned, ground-controlled rendezvous and docking procedures have been demonstrated on many Russian flights and have been proposed as an efficient technique for an unmanned Mars sample return mission. [57] In this section, we discuss rendezvous orbit dynamics and procedures.
Preliminary rendezvous maneuvers, often called phasing maneuvers, may well be analyzed in an inertial frame such as GCI and carried out using the methods of Sec. 4.4. However, the terminal phase of rendezvous involves the closure of two vehicles separated by distances that are small (e.g., tens or hundreds of kilometers) relative to the dimensions of the orbit. It is then expected that the difference in acceleration experienced by the two vehicles is relatively small and thus that their differential motion might easily be obscured by their gross orbital motion. Also, guidance algorithms are generally described in terms of the position and velocity of one vehicle relative to another. For these reasons, a description of the orbital motion and maneuvers in a planetary-centered reference frame is often inappropriate for rendezvous analysis.
