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...
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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”)
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CCSDS Member Agencies
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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
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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
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CCSDS Technical Organization Chart
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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
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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
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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
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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)
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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
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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.
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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.
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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.
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Spacecraft Maneuver Message (SMM) White Book
•  Standard message formats for exchanging information
regarding finite maneuver information
•  Data exchange involves both predicted & reconstructed
information related to intentional changes to orbit and
attitude using spacecraft actuators
•  Data are exchanged between flight dynamics groups and
flight ops teams for planning & calibration of maneuvers
•  Will address most common types of S/C maneuvers:
propulsive systems and reaction wheels
•  Examples of typical data: epoch and duration of the
maneuver; magnitude and direction of the orbit/attitude
change; desired change in orbit parameters; desired
change in attitude state, etc.
•  Also describes the onboard hardware used to effect the
change in the spacecraft orbit/attitude state
•  Current Status: Very early draft. Completion target 2016.
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Events Message (EVM) Concept Paper
•  Standard message formats for exchanging information
regarding predicted orbital events
•  Events are a major data type used in operations, e.g.:
•  Start/end of eclipses
•  Ground station visibilities AOS/LOS
•  When some geometric condition is met
•  Abstract “event” = epoch, name, supplementary info
•  EVM will be a collection of such event descriptions, often
paired (start/end of some condition or phenomenon)
•  “Event” concept is cross-cutting, thus event framework to
be defined by CCSDS System Engineering Area (SEA)
•  CNWG will define flight dynamics related events within the
SEA defined framework (common + mission defined)
•  Current Status: Concept paper. Completion target 2017?
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Operations Infusion Use Cases
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Contact Information / Useful Web Sites
•  Web Sites
•  www.ccsds.org – general web site of the CCSDS
•  Free access to standards and other publications
•  Review/comment on documents in progress
•  Meeting schedules and organizational information
•  http://cwe.ccsds.org/moims/default.aspx , then choose
the MOIMS-NAV tab on the far left menu
•  Can view draft documents in progress
•  E-mail Address
•  moims-nav@mailman.ccsds.org
•  Send an email if interested in participating in the WG
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Conclusion
•  When the original charter of the CCSDS Navigation
Working Group was fulfilled, a number of good ideas for
expanded standardization of flight dynamics operations
emerged
•  For the next few years, the CNWG "pipeline" is full, but
someday the "expanded" technical program will also be
fulfilled
•  As that time draws near, renewed effort to identify areas
for further standardization of flight dynamics data
exchange is desirable will be necessary
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Q&A
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BACKUP SLIDES
Orbit Data Messages (ODM)
•  Designation: CCSDS 502.0-B-2, ISO 26900:2012
•  Three standard message formats for exchanging orbit
descriptions
•  Orbit Parameter Message (OPM) is a state vector
•  Position/velocity at epoch; must propagate
•  Orbit Ephemeris Message (OEM) is an ephemeris
•  Position/velocity at multiple epochs; must interpolate
•  Orbit Mean Elements Message (OMM) is an orbit state
•  Mean Keplerian elements; must propagate
•  Infusion Status:
•  OEMs used in daily ESA/NASA operations
•  CCSDS Service Management Standard directly
incorporates XML OEM and OPM messages
•  Analytical Graphics Inc. (AGI) Orbit Determination
Toolkit (ODTK) can output a CCSDS OEM
•  GMV’s focussuite S/W implements KVN & XML ODM
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Tracking Data Message (TDM)
•  Designation: CCSDS 503.0-B-1, ISO 13526:2010
•  Standard message format for exchanging tracking data
•  TDM supports widely used tracking data types:
•  Ground-based radiometrics: transmit & receive
frequencies, Doppler, range, angle, ΔDOR
•  Ancillary information (e.g., meteorological, media
delays, clock bias/drift)
•  Produced by the deep space tracking networks of ESA,
NASA/JPL, ISRO, CNSA, JHU/APL; read by AGI/ODTK
•  Currently undergoing mandatory 5 year CCSDS review
•  Additional data types could be added during this review
•  Requests to add some new data types oriented to
optical tracking of space debris, support changes in the
TDRSS ground system, support GPS point solutions
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Attitude Data Messages (ADM)
•  Designation: CCSDS 504.0-B-1, ISO 13541:2010
•  Two standard message formats for exchanging spacecraft
attitude descriptions
•  Attitude Parameter Message (APM) is an attitude state at
epoch, must be propagated
•  Attitude Ephemeris Message (AEM) specifies a series of
attitude states at multiple epochs, allows modelling of any
number of torques, must be interpolated
•  Infusion Status: in daily use at NASA/GSFC
•  Such message exchanges are used for: preflight planning
for tracking or attitude estimation support; scheduling
attitude and data processing support; carrying out attitude
operations; performing attitude comparisons; carrying out
attitude propagations and/or sensor predictions; testing
•  Due for 5 year review in 2013
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Navigation Data Messages/XML Spec (NDMXML)
•  Designation: CCSDS 505.0-B-1, ISO 17107:2011
•  XML representations of CNWG messages requested by
CCSDS Management Council (CMC), in addition to the
KVN representations
•  Describes an integrated XML schema set for encoding
the ADM, ODM, and TDM (the Initial Technical Program)
•  Compatible with ODM 1.0, ODM 2.0, ADM 1.0, TDM 1.0
•  Full schema set is available via the CCSDS Space
Assigned Numbers Authority (SANA) Registry
•  First approved registry in the SANA repository
•  Different approach to XML representations being taken
in Expanded Technical Program
•  Both KVN and XML formats described directly in
standards documents rather than in separate volume
•  Reduces document reviews, increases efficiency
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