Viking Navigation

NASA soft-landed two Viking spacecraft on Mars in the summer of 1976. These were the free world's first landings on another planet. This report provides a final, comprehensive description of the navigation of the Viking spacecraft throughout their flight from Earth launch to Mars landing. The flight path design, actual inflight control, and postflight reconstruction ale discussed in detail. The report is comprised of an introductory chapter followed by five chapters which essentially correspond to the organization of the Viking navigation operations, namely, Trajectory Description, Interplanetary Orbit Determination, Satellite Orbit Determination, Maneuver Analysis, and Lander Flight Path Analysis. To tile extent appropriate, each chapter describes the preflight analyses upon which the operational strategies and performance predictions were based. The inflight results are then discussed and compared with the preflight predictions and, finally, the results of any postflight analyses are presented.