PROGRESS IN STANDARDIZING FLIGHT DYNAMICS DATA EXCHANGE David S. - - PowerPoint PPT Presentation

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

• 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

• f 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
• f 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

ISSFD 23

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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ISSFD 23

BACKUP SLIDES

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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

ISSFD 23

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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
• ptical 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

• perations; 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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