Richards, R. W. | Search NASA

NASA NTRS1982

Space Shuttle Interim Teleprinter System

This paper describes the Space Shuttle Interim Teleprinter System. The major design developments involved in selecting modifying, and testing a communications terminal for compatibility with the Space Shuttle communications system and crew are presented. The objective was to provide an onorbit capability to receive and reproduce text hardcopy data from the ground for crew activity changes. The Interim Teleprinter System is remotely controlled from the ground, and message retrieval requires minimal crew activity. It has performed well in flight, and has printed over 10,000 lines of text information to date while in earth orbit with no character errors.

Schuette, M. D.↗

NASA NTRS1978

A digital audio/video interleaving system

A method of interleaving an audio signal with its associated video signal for simultaneous transmission or recording, and the subsequent separation of the two signals, is described. Comparisons are made between the new audio signal interleaving system and the Skylab Pam audio/video interleaving system, pointing out improvements gained by using the digital audio/video interleaving system. It was found that the digital technique is the simplest, most effective and most reliable method for interleaving audio and/or other types of data into the video signal for the Shuttle Orbiter application. Details of the design of a multiplexer capable of accommodating two basic data channels, each consisting of a single 31.5-kb/s digital bit stream are given. An adaptive slope delta modulation system is introduced to digitize audio signals, producing a high immunity of work intelligibility to channel errors, primarily due to the robust nature of the delta-modulation algorithm.

Richards, R. W.↗