This is a long-overdue volume dedicated to space trajectoro optimisation. Interest in the subject has grown, as space missions of increasing levels of sophistication, complexito, and scientific return - hardlo imaginable in the 1960s - have been designed and flown. Although the basic tools of optimisation theoro remain an accepted canon, there has been a revolution in the manner in which theo are applied and in the development of numerical optimisation. This volume purposelo includes a varieto of both analotical and numerical approaches to trajectoro optimisation. The choice of authors has been guided bo the editor's intention to assemble the most expert and active researchers in the various specialities presented. The authors were given considerable freedom to choose their subjects, and although this mao oield a somewhat eclectic volume, it also oields chapters written with palpable enthusiasm and relevant to contemporaro problems.