PROGRESS IN STANDARDIZING FLIGHT DYNAMICS DATA EXCHANGE David S. Berry, Joseph Hashmall, Alain Lamy, Francisco Martinez Fadrique, Karen V. Richon, and Denise Snow 29-Oct-2012
Introduction • This presentation describes the CCSDS Navigation Working Group (CNWG) and its space flight dynamics international standards, published and in development • Primary relevance is promotion of interoperability between space agencies and operators • CNWG Technical Program has been presented at the ISSFD meetings in 2004 and 2007 • Focus of these two papers was exchanges of orbit data, attitude data, and tracking data • Since 2007, CNWG’s initial technical program has been completed • Since 2008, a number of new work items have been identified and added to an expanded technical program • Accordingly, it is time for an update... 29-Oct-2012 ISSFD 23 2
CCSDS and ISO Overview • Consultative Committee for Space Data Systems (CCSDS) founded in 1982 as a multi-national forum of the world’s space agencies • Develops international standards related to space data communications and data systems • To date, nearly 600 space missions have chosen to use CCSDS standards in one or more aspects of the mission • Formally affiliated with International Organization for Standardization (ISO), which includes as members the national standards bodies of 80% of the world's countries • Within ISO over 200 Technical Committees (TC), each focusing on a particular area of international commerce • CCSDS affiliation with ISO is via TC20 ("Aircraft and Space Vehicles") Subcommittee 13 (SC13, "Space Data and Information Transfer Systems”) 29-Oct-2012 ISSFD 23 3
CCSDS Member Agencies • Agenzia Spaziale Italiana (ASI)/Italy • Canadian Space Agency (CSA)/Canada • Centre National d ’ Etudes Spatiales (CNES)/France • China National Space Administration (CNSA)/People ’ s Republic of China • Deutsches Zentrum für Luft- und Raumfahrt (DLR)/ Germany • European Space Agency (ESA)/Europe • Federal Space Agency (FSA)/Russian Federation • Instituto Nacional de Pesquisas Espaciais (INPE)/Brazil • Japan Aerospace Exploration Agency (JAXA)/Japan • National Aeronautics & Space Administration (NASA)/USA • UK Space Agency/United Kingdom 29-Oct-2012 ISSFD 23 4
CCSDS & the Navigation Working Group • Management provided by the CCSDS Management Council (CMC) • Technical work guided by the CCSDS Engineering Steering Group (CESG) • CCSDS consists of 6 general “ Areas ” • Areas are partitioned into approximately 30 smaller groups called “ Working Groups ” (WG), “ Special Interest Groups ” (SIG) and “ Birds of a Feather Groups ” (BOF) • Each WG, SIG or BOF is associated with an Area • CNWG is part of CCSDS Mission Operations and Information Management Services Area (MOIMS) • Charter is to produce CCSDS Recommendations related to the formatting and exchange of flight dynamics data • Goal is to increase flight dynamics interoperability 29-Oct-2012 ISSFD 23 5
CCSDS Technical Organization Chart 29-Oct-2012 ISSFD 23 6
CCSDS Standards Development Process • A “ Concept Paper ” suggests a need for standardization • A Working Group develops recommendation via consensus • Recommendation documents go through several stages: Proposed (White), Draft (Red), final (Blue), revised (Pink) • White Books are internal to the Working Group • When White Book matures, promotion to Red Book • Formal Agency Review process commences (2-3 months) • When Agency Review is passed, prototyping is complete and test reports filed, promotion to Blue Book can occur • ISO standards process entered at advanced stage (DIS/FDIS) • Blue Books undergo 5 year reconfirmation review • Revised Blue Books enter a draft stage colored “ Pink ” • A “ Green Book ” is a non-normative technical report • A “ Silver Book ” is historic, no longer normative • CNWG has books in all of these categories 29-Oct-2012 ISSFD 23 7
CNWG Participating Membership • The CCSDS Navigation Working Group has had regular participation from the following space agency/organizations: • CNES • DLR • ESA • JAXA • NASA • ISO TC20/SC14/WG3 (Nav WG “ sister organization ” ) • A few agencies have named representatives in the past but have not recently participated • Some agencies participate in CCSDS but have not been involved in CNWG • Support from commercial & military entities also received 29-Oct-2012 ISSFD 23 8
CNWG Initial Technical Program and the ISSFD • At the time of the 18th ISSFD in 2004, the CNWG was working on five documents: • Orbit Data Messages (ODM) • Tracking Data Message (TDM) • Attitude Data Messages (ADM) • An XML representation of the ODM, TDM, and ADM • An update to the "Green Book” • Only the Green Book had been published • By the time of the 20th ISSFD in 2007, ODM had been published but was undergoing a semi-major revision; the ADM and TDM were relatively close to being completed • Since 2007, all documents in the CNWG initial technical program have been published (the last one in 2010), and all have achieved some level of operations infusion 29-Oct-2012 ISSFD 23 9
CNWG Documents ( “ Color Coded ” ) • Initial Technical Program • Orbit Data Messages (ODM) • Tracking Data Message (TDM) (up for 5 year review) • Attitude Data Messages (ADM) • Navigation Data Messages / XML Specification • Expanded Technical Program • Conjunction Data Message (CDM) • Pointing Request Message (PRM, White Book) • Navigation H/W Message (NHM, White Book) • Spacecraft Maneuver Msg (SMM, White Book) • Events Message (EVM, Concept Paper) 29-Oct-2012 ISSFD 23 10
CNWG Expanded Technical Program • Recognizing that its original charter was nearly complete, in Fall 2008 CNWG began considering new opportunities for standardization of flight dynamics data exchange • CNWG principles first described at ISSFD in 2004 not changed • Maximum commonality between recommendations • Clear definition of units • Ease of transition from a KVN specification to an XML specification • Flexibility to include additional information, such as comments and optional parameters • Identification of non-standard items to be addressed in an Interface Control Document (ICD) • Next sections of this presentation briefly describe new standards in development, in order of relative maturity 29-Oct-2012 ISSFD 23 11
Conjunction Data Message (CDM) • Specifies a standard message format for exchanging spacecraft conjunction information between originators of conjunction assessments and spacecraft operators • Contains information about a single conjunction event between two space objects • Provides data for satellite operators to use in making decisions regarding whether and how to maneuver • Requires position, velocity, miss distance and covariance of the two objects at the time of closest approach (TCA) • Optionally contains relative position, relative velocity, probability of collision at TCA, OD quality “indicators” • An example CDM is in the paper • Current Status: Recently completed CCSDS Agency Review process, prototyping in progress. Completion target in first half of 2013. 29-Oct-2012 ISSFD 23 12
Pointing Request Message (PRM) White Book • Standard message formats for transmission of complex pointing requests in formal language • The requested pointing could be of a S/C instrument or of an onboard-antenna • Reduces errors associated with providing pointing requests in common language • Complex task when the satellite is operated by one agency but requests come from others • PRM identifies S/C, onboard instrument, various rates and constraints, applicable epochs, etc. • Incorporates a collection of generic pointing templates such as inertial, limb, terminator, velocity, nadir, & track • Current Status: Relatively early in development, however, an operational prototype exists at ESA/ESOC, so it is also relatively far into the process. Completion target 2014. 29-Oct-2012 ISSFD 23 13
Navigation Hardware Message (NHM) White Book • Standard message formats for exchange of navigation hardware data • Data includes attitude & navigation sensor data, actuator data, and data produced by the onboard GN&C system • This data is used to produce prediction, determination, and reconstruction of spacecraft attitude and/or trajectory • Number and variety of H/W data types is large and constantly changing, so NHM is designed to be extensible and transmit data from arbitrary hardware • The standard specifies a syntax in which hardware data can be unambiguously defined and the data then reported • Provides the versatility, clarity, and standardization that will improve the utility of Navigation Hardware Data • Current Status: NHM is still very early in CCSDS standards development process. Completion target 2015. 29-Oct-2012 ISSFD 23 14
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