VITERBI DECODER FOR NASA’S SPACE SHUTTLE’S TELEMETRY DATA

Abstract

In the event of a NASA Space Shuttle mission landing at the While Sands Missile Range, White Sands, New Mexico, a data communications system for processing Shuttle’s telemetry data has been installed there in the Master Control Telemetry Station, JIG-56. This data system required a Viterbi decoder since the Shuttle’s data is convolutionally encoded. However, the Shuttle uses a nonstandard code, and the manufacturer which in the past has provided decoders for Shuttle support, no longer produces them. Since no other company produced a Viterbi decoder designed to decode the shuttle’s data, it was necessary to develop the required decoder. The purpose of this paper is to describe the functional performance requirements and design of this decoder.