Keeping Communication Continuous

About this technology

Overview

General Dynamics Decision Systems collaborated with Goddard Space Flight Center to develop transponders, wireless communications devices that pick up and automatically respond to an incoming signal, for NASA's Tracking and Data Relay Satellite System (TDRSS). The company's Fourth Generation TDRSS User Transponder allows low-Earth-orbiting spacecraft to communicate continuously with a single ground station at White Sands, New Mexico, through a constellation of geo-stationary relay satellites positioned at key locations around the Earth. In addition to the communications of forward link control commands and return link telemetry data, the TDRSS IV also supports spacecraft orbit tracking through coherent turn-around of a pseudo-noise ranging code and two-way Doppler tracking. A new product, the Multi-Mode Transceiver (MMT), has a reduced size, weight, power consumption, and cost, to bring the advantages of TDRSS communications to a variety of applications outside of the traditional NASA spacecraft missions. With the MMT, the NASA system is now accessible to university satellite programs, small commercial Earth imaging programs, as well as Arctic and Antarctic science programs.