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Radio science receiver support of the Mars Exploration Rover LandingsThe low power levels of the communication signals during the Entry Descent and Landing (EDL) sequences of the Mars rovers prevented the transmission of telemetry at X-band signal to inform the mission operations center of the health and progress of the spacecraft. As an altemative, a series of tones were sent to indicate basic spacecraft conditions and execution of critical events. An open-loop receiver designed for Radio Science experiments was used to acquire the signal during this time. The receiver recorded over a 100 Khz bandwidth to identify the presence of the carrier and tones. The data were fed in real-time to a processing unit which detected the carrier and the frequency separation of the tones from the carrier, in order to determine which event has occurred. Up to 256 different tones were possible. During the actual events, all tones were identified, and the carrier was tracked down to the surface, and for the second rover, through the bouncing which followed, and finally, while stopped on the surface, found the carrier and tones which indicated the spacecraft was alive. In order to identify the tones, the ground receivers had to be able to respond to the bevy of events occurring in the relatively short timespan of EDL.
Document ID
20060043872
Acquisition Source
Jet Propulsion Laboratory
Document Type
Conference Paper
External Source(s)
Authors
Johnston, Douglas
Asmar, Sami
Chang, Christine
Estabrook, Polly
Finely, Sue
Pham, Timothy
Satorius, Edgar
Date Acquired
August 23, 2013
Publication Date
September 7, 2004
Subject Category
Lunar And Planetary Science And Exploration
Meeting Information
Meeting: 3rd International Workshop on Tracking Commands Systems
Location: Darmstadt
Country: Germany
Start Date: September 7, 2004
End Date: September 10, 2004
Distribution Limits
Public
Copyright
Other
Keywords
Deep Space Network (DSN)
Entry Descent and Landing (EDL)
communications

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