Phil Liebrecht Assistant Deputy Associate Administrator and Deputy Program Manager Space Communications and Navigation NASA HQ Meeting the Communications and Navigation Needs of Space missions since 1957 “Keeping the Universe Connected” Public University of Navarra, 2010
[email protected] 1 Operations and Communications Customers 2 Space Operations 101 Relation Between Space Segment, Ground System, and Data Users* Ground System Command Commands Requests Spacecraft and Payload Support • Mission Planning Telemetry • Flight Operations • Flight Dynamics • Perf. Assess., Trending & Archiving Space Data Users • Anomaly Support Segment Data Relay and Level (S/C) Mission Zero Data Processing Mission Data Data • Space-to-ground Comm. • Data Capture • Data Processing • Network Management • Data Distribution • Quick Look * Based on Wertz and Wiley; Space Mission Analysis and Design 3 Communications Theory- Basic Concepts Transmitter and Receiver must use the same language Noise causes interference a) Figures it – no errors (Identify and quantify) b) Figures it – corrects Must be loud enough ENERGY! c) Figures it – incorrectly (message in error) d) Cannot figure- recognizes E L an error T M E XP AIN L E e) Cannot figure- ? TRANSMITTER Distance weakens the sound RECEIVER (calculate the loss) CHANNEL Has to correctly interpret the message - the most difficult job The fundamental problem of communications is that of reproducing at one point either exactly or approximately a message selected at another point. 4 Functional - End to End Process