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dc.contributor.authorBusby , Lawrence A.
dc.contributor.authorKramb, Edwin A.
dc.date.accessioned2016-06-29T21:23:09Z
dc.date.available2016-06-29T21:23:09Z
dc.date.issued1981-10
dc.identifier.issn0884-5123
dc.identifier.issn0074-9079
dc.identifier.urihttp://hdl.handle.net/10150/615100
dc.descriptionInternational Telemetering Conference Proceedings / October 13-15, 1981 / Bahia Hotel, San Diego, Californiaen_US
dc.description.abstractFlight Termination Sub-Systems for range safety purposes are a part of all spacecraft launch vehicles. The Command Receiver and Decoder portion of this sub-system receives the rf up-link signal and initiates the flight termination action. For launch vehicles for unmanned spacecraft, the range safety up-link command signal is composed of selected IRIG audio tones, in a specified sequence, frequency modulated on an rf carrier. For the Space Shuttle launches, a more sophisticated high-alphabet modulation technique is used. This provides for a better probability against an undesired output caused by interfering signals. The Shuttle system uses a complex command modulation format composed of various audio tones frequency modulated on the standard UHF carrier. The characters in the command word are made up of two simultaneously transmitted tones selected from seven possible frequencies. These seven tones, taken two at a time, provide an alphabet of twenty-one different characters from which a command word is formed. The transmitted sequence of characters is selectable from mission to mission. Approximately 1012 possible code combinations exist for any one mission. For the Space Shuttle launches, the range safety Command Receiver-Decoders will be used on the Solid Rocket Boosters and the External Tank portions of the complex launch vehicle. The receiver section of these units is a single superheterodyne design fixed tuned to the proper rf center frequency at the time of manufacture. The decoder section utilizes a microprocessor to effect the decoding function. The decoder is “programmed” prior to flight to recognize only the code of the mission. In addition, the microprocessor is used to accomplish the audio tone demodulation using a Fast Fourier Transform (FFT) algorithm. Solid state output switches provide the decoder output voltages to the flight termination destruct mechanism.
dc.description.sponsorshipInternational Foundation for Telemeteringen
dc.language.isoen_USen
dc.publisherInternational Foundation for Telemeteringen
dc.relation.urlhttp://www.telemetry.org/en
dc.rightsCopyright © International Foundation for Telemeteringen
dc.titleRANGE SAFETY RECEIVER-DECODER FOR SPACE SHUTTLE LAUNCH VEHICLEen_US
dc.typetexten
dc.typeProceedingsen
dc.identifier.journalInternational Telemetering Conference Proceedingsen
dc.description.collectioninformationProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection.en
refterms.dateFOA2018-08-15T13:04:43Z
html.description.abstractFlight Termination Sub-Systems for range safety purposes are a part of all spacecraft launch vehicles. The Command Receiver and Decoder portion of this sub-system receives the rf up-link signal and initiates the flight termination action. For launch vehicles for unmanned spacecraft, the range safety up-link command signal is composed of selected IRIG audio tones, in a specified sequence, frequency modulated on an rf carrier. For the Space Shuttle launches, a more sophisticated high-alphabet modulation technique is used. This provides for a better probability against an undesired output caused by interfering signals. The Shuttle system uses a complex command modulation format composed of various audio tones frequency modulated on the standard UHF carrier. The characters in the command word are made up of two simultaneously transmitted tones selected from seven possible frequencies. These seven tones, taken two at a time, provide an alphabet of twenty-one different characters from which a command word is formed. The transmitted sequence of characters is selectable from mission to mission. Approximately 1012 possible code combinations exist for any one mission. For the Space Shuttle launches, the range safety Command Receiver-Decoders will be used on the Solid Rocket Boosters and the External Tank portions of the complex launch vehicle. The receiver section of these units is a single superheterodyne design fixed tuned to the proper rf center frequency at the time of manufacture. The decoder section utilizes a microprocessor to effect the decoding function. The decoder is “programmed” prior to flight to recognize only the code of the mission. In addition, the microprocessor is used to accomplish the audio tone demodulation using a Fast Fourier Transform (FFT) algorithm. Solid state output switches provide the decoder output voltages to the flight termination destruct mechanism.


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