Large round trip delay associated with satellite channels reduces the throughput for automatic repeat-request (ARQ) system of error control rather drastically under high error rate conditians. Ground segments that usually accompany satellite circuits at both ends introduce bursts of errors, during which block error rates tend to be quite high, bringing down the throughput to very low values. In this paper, some schemes that modify the currently known variations of ARQ (Stop-and-Wait and continuous systems) are suggested with a view to obtaining higher throughput under high block error rate conditions. Specifically, the modified Go-Back-

system appears to be quite attractive, as it gives substantial improvement with little additional complexity in system implementation.