The analysis and computational techniques associated with the navigation and guidance of spacecraft are now in a mature state of development. However the documentation has remained dispersed throughout conference papers, journals, company and contract rep orts, making it difficult to get a true, comprehensive picture of the subject. This text brings together the body of literature with suitable attention to the necessary underlying mathematics and computational techniques. It covers in detail the necessary orbital mechanics, orbit determination with emphasis on the SRIF algorithm, gr avity...