2 - The phases of a rendezvous mission

Summary

The purpose of this chapter is to give the reader a short overview of the different phases of a rendezvous approach and to describe the major issues of these phases. It is hoped that it will be easier, after familiarisation with the basic concept of a rendezvous mission, for the reader to put the information given in the subsequent chapters into their proper context. For this reason, some of the information provided in more detail in the later chapters had to be duplicated in condensed form here.

A rendezvous mission can be divided, as indicated in figure 2.1, into a number of major phases: launch, phasing, far range rendezvous, close range rendezvous and mating. During these phases, the kinematic and dynamic conditions that will eventually allow the connection of the chaser to the target spacecraft are successively established. In the following sections of this chapter an overview of the objectives, the end conditions to be achieved and the trajectory implementation possibilities of each of those phases will be given. This includes a rough order of magnitude of the major performance values which the guidance, navigation and control system of the chaser will have to achieve. For completeness, a short section on departure has been added, which addresses the issues and constraints of separation from and moving out of the vicinity of the target station. The mission phases between mating and departure and after departure are not addressed as they are both, in objective and concept, fully independent of the rendezvous mission.