CCSDS 508.0-R-1, Conjunction Data Message (Red Book, Issue 1 ...

DRAFT CCSDS RECOMMENDED STANDARD FOR CONJUNCTION DATA MESSAGESTable B-2: Heritage RequirementsID Requirement Rationale TraceCDM-H01The CDM shall be provided in, orshall include, an ASCII format.ASCII character-based messagespromote interoperability. ASCIImessages are useful in transferringdata between heterogeneouscomputing systems, because theASCII character set is nearlyuniversally used and is interpretableby all popular systems. In addition,direct human-readable dumps of textto displays, emails, documents orprinters are possible withoutpreprocessing.3.1, 4.2CDM-H02The CDM shall not require softwaresupplied by other Agencies.This principle was agreed upon earlyin the history of the CCSDS NavigationWorking Group.n/aTable B-3: Desirable CharacteristicsID Requirement Rationale TraceCDM-D01CDM-D02CDM-D03CDM-D04CDM-D05The CDM should be extensible withno disruption to existing users/uses.The CDM should be as consistentas reasonable with any relatedCCSDS Recommended Standardsused for earth-to-spacecraft orspacecraft-to-spacecraftapplications.CDM originators should maintainconsistency with respect to theoptional keywords provided in theirimplementations; i.e., thecomposition of the CDMs providedshould not change on a frequentbasis.The CDM should allow the option fororiginators to provide a probability ofcollision of the two objects involvedin the conjunction.The CDM should provide informationwith which each object’s sphericalradius may be calculated.Space agencies and operatorsupgrade systems and processes onschedules that make sense for theirorganizations. In practice, someorganizations will be early adoptersbut others will opt to wait untilperformance of a new version of theCDM has been proven in otheroperations facilities.Ideally, the set of RecommendedStandards developed by a givenCCSDS Working Group will beconsistent.Implementations that change on afrequent basis do not promote stableoperations or interoperability.Some CDM originators will beinterested in providing this datum.Cited as desirable by ISO 16158(reference [D2]).The object radius is required forcalculation of collision probability inmost methods, which usually modelobjects as spheres given the lack ofattitude information.Table 3-1n/an/aTable 3-2Table 3-4CCSDS 508.0-R-1 Page B-4 March 2012