Surveyor Spacecraft Telecommunications

Abstract

Although the Surveyor program is five years old, very little concerning the on-board telecommunications has been recently printed. Because much interest has been stimulated by the recent very successful Surveyor I mission, it is believed that this descriptive article of the Surveyor telecommunications system will be of general interest. The paper is oriented toward actual subsystem implementation and performance, rather than the purely analytical presentation. The reliability and flexibility of the telecommunications is detailed with some attention being given to the operational redundancy and variety of data transmission modes available. A few of the major difficulties experienced during the design and qualifications of the telecommunications equipment are touched upon, with commentary on the solutions finally used. Pertinent mission data is discussed, with a brief presentation of some telemetered AGC: signals. Finally, a summary of the experiments run on the telecommunications subsystem, both in-flight and on the lunar surface, are presented. These experiments included a deliberate in-flight increase in the data rate above the analytically predicted level for an acceptable bit error rate, a mapping of the planar array antenna gain while on the lunar surface, voice transmission via the Surveyor transponder, and subsystem performance assessments. This paper presents the results of one phase of research carried out at the Jet Propulsion Laboratory, California Institute of Technology, under Contract No. NAS7-100, sponsored by the National Aeronautics and Space Administration.