This paper discusses the data system requirements for large space vehicles and describes a flexible telemetry system design which is used on all stages of the Saturn IB and Saturn V vehicles. The basic vehicle telemetry design provides standard assembly building blocks forming a versatile catalogue of parts from which a stage telemetry subsystem may be assembled to meet almost any conceivable monitoring requirement. In addition to its inflight monitoring function, the telemetry subsystem also provides real time data acquisition for automatic vehicle checkout.