Future timing accuracy requirements and procedures for data processing

Timing accuracy requirements for satellite experiment data are discussed. Although time accuracies of 100 milliseconds were sufficient when OSO-3, 4, 5 were launched in the mid-60s, time accuracies of 100 microseconds are necessary for OSO-8, HEAO-A, and Seasat, and it is thought likely that accuracies of 10 microseconds will become routine in the 1980s. An approach to the problem of identifying the sources of spacecraft timing errors - from the onboard counters to the final tagging of data - is considered.