Draft Recommendation for Space

DRAFT RECOMMENDATION FOR SPACE

DATA SYSTEM STANDARDS

SPACE LINK EXTENSION- SERVICE MANAGEMENT:
Service SPECIFICATION
(Trajectory Section)

CCSDS 910.11-W-???

White Book

February 2004

8Trajectory Specification

8.1Trajectory Overview

A trajectory specifies a set of spatial co-ordinates for the position and movement of a spacecraft, and the time period for which those co-ordinates are valid. They are provided by the UM so that the CM can check that the spacecraft is visible to the antenna it plans to use to make contact with the spacecraft during the period specified in the Service Request.

At least one trajectory file must be resident at the Complex for each RF link session in order for the antenna to be pointed correctly during that link session. Multiple trajectory files must be resident at the Complex for a given link session if the mission intends to perform maneuvers during that session, to allow for different outcomes of the maneuver.

The configuration profile use case is concerned with the operations that allow the UM to establish, control, and monitor the set of trajectory files that are resident at the Complex. The trajectory use case has the following component use cases:

a)new trajectory

b)replace trajectory

c)delete trajectory

d)query trajectory

as illustrated in Figure 8.1.

Figure 8.1: Trajectory Use Cases (View 40000)

Table 8.1 identifies the numbering scheme used in specifying the logical entities that comprise the trajectory use case. These include:

a)diagrammatic overviews of trajectory, distributed throughout this section [40000 to 40999]

b)the trajectory data model, including lists and descriptions of the trajectory attributes [41000 to 44999]

c)rules and requirements applicable to trajectory and its attributes [45000 to 45999]

d)operation rules for the new, replace, delete and query trajectory operations [46000 to 49999]

Table 8.1: Trajectory Series Logical Overview

40000 - 40999 / Trajectory Overviews
41000 - 41999 / Trajectory Class
42000 - 42999 / Orbit Ephemeris Message Class
43000 - 43999 / Orbit Parameter Message Class
44000 - 44999 / Position and Velocity Vector Class
45000 - 45999 / Trajectory Rules and Requirements
46000 - 46999 / New Trajectory Operation Rules
47000 - 47999 / Replace Trajectory Operation Rules
48000 - 48999 / Delete Trajectory Operation Rules
49000 - 49999 / Query Trajectory Operation Rules

Section 8.2 defines the trajectory data model. (Note to reader: there are no processing rules defined in this section as this specifies the general carrier profile and it composition, not the operations.) Sections 8.3 through 8.6 define those operations used by UM to create, replace, delete and query each trajectory file that exists at the CM.

8.2TRAJECTORY INFORMATION model

Figure 8.2 is an informal overview of the information model containment for the trajectory class. Figure 8.3 is a UML class diagram of the trajectory data entities, their identification, and top-level relationship with respect to the taxonomy in Table 8.1.

Note – The use of classes in the UML diagram is primarily for the purpose of illustrating relationships among different aggregations of information. It is not intended to imply an implementation approach.

Figure 8.2: Trajectory Containment Diagram (View 40001)

Figure 8.3: Trajectory UML Class Diagram (View 40002)

8.2.1Trajectory Classes

The trajectory comprises the following classes [entity id]:

Trajectory [41000]
Orbit Ephemeris Message [42000]
Orbit Parameter Message [43000]
Position and Velocity Vector [44000]

8.2.2Data Entity Contents

The attributes of the classes that comprise the trajectory are defined in Tables 8.2 to 8.5.

Table 8.2 includes the basic trajectory attributes.

Table 8.2: Trajectory Class Attributes (41000)

Attribute # / Attribute Name / Attribute Definition/Description / Data Type / Units
41000 / trajectoryId / Unique identifier of the trajectory invocation, relative to the service agreement for the service request. / String / N/A
41001 / TractoryStartTime / Specifies the time from which the trajectory file is valid. / UTCTimeType / MM:DD:
HH:MM:SS
41002 / TractoryStopTime / Specifies the time at which the trajectory file is no longer valid. / UTCTimeType / MM:DD:
HH:MM:SS
21001 / serviceAgreementId / Service Agreement ID that is applicable to the spacecraft / String / N/A

Table 8.3 includes the attributes of the trajectoryFormat option, orbitEphemerisMessage (OEM). The OEM specifies the position and velocity of the spacecraft at the time specified in the message. The OEM requires the use of an interpolation technique by the CM to calculate the position and velocity of the spacecraft at times between those specified in a series of OEMs.

Table 8.3: Orbit Ephemeris Message Class Attributes

Attribute # / Attribute Name / Attribute Definition/Description / Data Type / Units
42000 / version
(in oemHeader) / Specifies the version of the oem specification used for this message. Default is 1.0. / String / N/A
42001 / creationTime
(in oemHeader) / Specifies the date and time the message was created.
e.g. 2004-02-19T18:49:05 / UTCTimeType / YYYY:MM:DD:
HH:MM:SS
42002
to 42009 / Not Used
42010 / objectName
(in ephemerisMetaData
in oemBody) / This is the spacecraft name (could be from the Spacewarn Bulletin).
e.g. Mars Express, STS 106 / String / N/A
42011 / objectId
(in ephemerisMetaData
in oemBody) / International spacecraft identifier in the format YYYY-NNNP{PP}
e.g. 2004-023A / String / N/A
42012 / centerName
(in ephemerisMetaData
in oemBody) / Origin of Reference Frame
e.g. Earth, Earth Barycenter, Moon, Mars, STS 106 / String / N/A
42013 / referenceFrame
(in ephemerisMetaData
in oemBody) / One of …
ICRF, ITRF-93, ITRF-97, ITRF2000, TOD, EME1950 or EME2000 / String / NA
42014 / timeSystem
(in ephemerisMetaData
in oemBody) / One of …
UTC, TAI, TT, GPS, TDB, TCB / String / NA
42015 / startTime
(in ephemerisMetaData
in oemBody) / Start of the timespan covered by this message.[HK1] / DateTime specified in timeSystem / YYYY:MM:DD:
HH:MM:SS
42016 / stopTime
(in ephemerisMetaData
in oemBody) / End of the timespan covered by this message. / DateTime specified in timeSystem / YYYY:MM:DD:
HH:MM:SS
42017 / useableStartTime
(in ephemerisMetaData
in oemBody) / Start of the useable timespan covered by this message (depends on the interpolation method used). / DateTime specified in timeSystem / YYYY:MM:DD:
HH:MM:SS
42018 / useableStopTime
(in ephemerisMetaData
in oemBody) / End of the useable timespan covered by this message (depends on the interpolation method used). / DateTime specified in timeSystem / YYYY:MM:DD:
HH:MM:SS
42019 / Not used
42020 / comment
(in ephemeris
in oemBody) / Free text to help clarify the message e.g. assumed interpolation method used. / String / NA

Table 8.4 includes the attributes of the trajectoryFormat option, orbitParameterMessage. In this option, it is assumed that the CM has the capability to propagate the orbit and model the effects of gravitational forces, solar radiation pressure, atmospheric drag and thrust phases, to the extent agreed between the UM and CM in the Service Agreement.

Note – We need to check that the Service Agreement covers this.

Table 8.4: Orbit Parameter Message Class Attributes

Attribute # / Attribute Name / Attribute Definition/Description / Data Type / Units
43000 / version
(in opmHeader) / Specifies the version of the oem specification used for this message. Default is 1.0. / String / N/A
43001 / creationTime
(in opmHeader) / Specifies the date and time the message was created.
e.g. 2004-02-19T18:49:05 / UTCTimeType / YYYY:MM:DD:
HH:MM:SS
43002
to 43009 / Not Used
43010 / objectName
(in opmIdentification) / This is the spacecraft name (could be from the Spacewarn Bulletin).
e.g. Mars Express, STS 106 / String / N/A
43011 / objectId
(in opmIdentification) / International spacecraft identifier in the format YYYY-NNNP{PP}
e.g. 2004-023A / String / N/A
43012 / centerName
(in opmIdentification) / Origin of Reference Frame
e.g. Earth, Earth Barycenter, Moon, Mars, STS 106 / String / N/A
43013 / referenceFrame
(in opmIdentification) / One of …
ICRF, ITRF-93, ITRF-97, ITRF2000, TOD, EME1950 or EME2000 / String / NA
43014 / timeSystem
(in opmIdentification) / One of …
UTC, TAI, TT, GPS, TDB, TCB / String / NA
43015 / startTime
(in ephemerisMetaData
in oemBody) / Start of the timespan covered by this message.[HK2] / DateTime specified in timeSystem / YYYY:MM:DD:
HH:MM:SS
43016
to 43019 / Not used
43020 / comment
(in maneuvers
in opmBody) / Free text to help clarify the message. / String / NA
43021 / maneuverEpochIgnition
(in maneuvers
in opmBody) / Time of start of planned maneuver
e.g. 2004-05-22T18:25:15 / DateTime specified in timeSystem / MM:DD:
HH:MM:SS
43022 / manueverDuration
(in maneuvers
in opmBody) / Duration of planned maneuver
If = 0, impulsive maneuver / Duration / SS
43023 / maneuverDeltaMass
(in maneuvers
in opmBody) / Mass loss as a result of the maneuver / Double / kg
43024 / maneuverReferenceFrame
(in maneuvers
in opmBody) / Coordinate system for velocity increment vector / String / NA
43025 / ManeuverDVComponent_1
(in maneuvers
in opmBody) / 1st component of the velocity increment / Double / km/s
43026 / ManeuverDVComponent_2
(in maneuvers
in opmBody) / 2nd component of the velocity increment / Double / km/s
43027 / ManeuverDVComponent_3
(in maneuvers
in opmBody) / 3rd component of the velocity increment / Double / km/s
43027
to 43029 / Not used
43020 / mass
(in spacecraftParameters
in opmBody) / Spacecraft mass at epoch / Double / kg
43031 / solarRadiationPressureArea
(in spacecraftParameters
in opmBody) / AR / Double / m2
43032 / solarRadiationCoefficient
(in spacecraftParameters
in opmBody) / CR / Double / m2
43033 / dragArea
(in spacecraftParameters
in opmBody) / AD / Double / m2
43034 / dragCoefficient
(in spacecraftParameters
in opmBody) / CD / Double / N/A
43034
to 43039 / Not used
43040 / semiMajorAxis
(in keplerianElements
in opmBody) / Semi-major Axis / Double / km
43041 / eccentricity
(in keplerianElements
in opmBody) / Eccentricity / Double / Deg:m:s
43042 / inclination
(in keplerianElements
in opmBody) / Inclination / Double / Deg:m:s
43043 / rightAscensionOfAscendingNode
(in keplerianElements
in opmBody) / Right Ascension of Ascending Node / Double / Deg:m:s
43044 / argumentOfPericenter
(in keplerianElements
in opmBody) / Argument of Pericenter / Double / Deg:m:s
43045 / trueAnomaly
(in keplerianElements
in opmBody) / Either trueAnomaly or meanAnomaly is specified / Double / Deg:m:s
43046 / meanAnomaly
(in keplerianElements
in opmBody) / Either trueAnomoly or meanAnomaly is specified / Double / Deg:m:s
43047 / gravitationalCoefficient
(in keplerianElements
in opmBody) / This is the product of the Gravitational Constant (G) and the central mass – only needed for conversion between Keplerian elements and state vectors / Double / km3/s2

Table 8.5 includes the attributes of the positionAndVelocityVector class, which are common to both the orbitEphemerisMessage and the orbitParameterMessage.

Table 8.5: Position and Velocity Vector Class Attributes

Attribute # / Attribute Name / Attribute Definition/Description / Data Type / Units
44000 / epoch
(in ephemerisData
in ephemeris
in oemBody) / Epoch of state vector
e.g. 2004-05-22T18:00:00 / DateTime specified in timeSystem / YYYY:MM:DD:
HH:MM:SS
44001 / x
(in ephemerisData
in ephemeris
in oemBody) / X-component of position vector / float / km
44002 / y
(in ephemerisData
in ephemeris
in oemBody) / Y-component of position vector / float / km
44003 / z
(in ephemerisData
in ephemeris
in oemBody) / Z-component of position vector / float / km
44004 / xDot
(in ephemerisData
in ephemeris
in oemBody) / X-component of velocity vector / float / km/s
44005 / yDot
(in ephemerisData
in ephemeris
in oemBody) / Y-component of velocity vector / float / km/s
44006 / zDot
(in ephemerisData
in ephemeris
in oemBody) / Z-component of velocity vector / float / km/s

8.2.3Data Entity Composition and Relationship Requirements, Trajectory

45000 / The trajectoryId [41000] data item must be unique relative to the Service Agreement [20000].
45001 / A trajectory [41000] must contain either one EPM [42000] or one OPM [43000].
45002 / The EPM and OPM must contain one Position and Velocity Vector [44000].
45003 / When the Keplerian elements in an OPM are used, they must contain either a true anomaly [43045] or a mean anomaly [43046] but not both.
45004 / Only one set of position and velocity data is provided per trajectory message. The UM therefore needs to provide the CM with a series of trajectory messages at sufficient time intervals for the CM to track the spacecraft reliably.
45005 / To be completed
45006
45007
45008
31310
31311
31312

8.3New TRajectory OperaTION

The new trajectory operation shall be supported by invocation and return interactions. Figure 8.4 illustrates the new carrier profile operation activities of UM and CM

8.3.1New Trajectory Invocation (UM  CM)

The new trajectory invocation comprises:

All attributes in [41000]

Either all attributes in [42000] or [43000]

All attributes in [44000]

8.3.2New Trajectory Successful Return (CM  UM)

The new trajectory successful return comprises:

8.3.3New Trajectory Failed Return (CM  UM)

The new trajectory failed return comprises:

Attribute # / Attribute Name / Attribute Definition/Description / Data Type / Units
41100 / trajectoryRef / Unique identifier of the trajectory as supplied by the CM in a trajectory return. / String / N/A
41210 / erredItem / Contains the identifier of an erroneous element in the new trajectory invocation / String / N/A
41211 / additionalInformation / Provides additional information about the error condition. / String / N/A
41212 / Diagnostic / What does this provide? / String / N/A

8.3.4New Trajectory AcknowlEdged Return (CM  UM)

The new trajectory failed return comprises:

Attribute # / Attribute Name / Attribute Definition/Description / Data Type / Units
41100 / trajectoryRef / Unique identifier of the trajectory as supplied by the CM in a trajectory return. / String / N/A
41220 / ExpectedDispositionTime
(in trajectoryAcknowledged) / UTCTimeType / YYYY:MM:DD:
HH:MM:SS
41221 / acknowledgementComment
(in trajectoryAcknowledged) / String / N/A

8.3.5UM Requirements for New Trajectory Operation

46000 / UM must check that the invocation conform to all Data Entity Composition and Relationship Requirements when issuing a new trajectory invocation.
46001 / To be completed

8.3.6CM Requirements for New Trajectory Operation

46100 / CM must validate that the new trajectory invocation conforms to the Data Entity Composition and Relationship Requirements. CM shall reject a new trajectory invocation that does not meet this criterion.
46101 / If a new trajectory invocation is rejected, CM shall return new trajectory failed to UM, identifying at least one of the invalid entities and its reason for invalidity. CM should identify as many invalid entities and accompanying reasons as possible.
46102 / To be completed

8.4Replace TRajectory OperaTION

The replace trajectory operation shall be supported by invocation and return interactions. Figure 8.5 illustrates the new carrier profile operation activities of UM and CM

8.4.1Replace Trajectory Invocation (UM  CM)

The replace trajectory invocation comprises:

All attributes in [41000] except trajectoryId, which is replaced by trajectoryRef

Either all attributes in [42000] or [43000]

All attributes in [44000]

8.4.2Replace Trajectory Successful Return (CM  UM)

The replace trajectory successful return is identical to the new trajectory successful return.

8.4.3Replace Trajectory Failed Return (CM  UM)

The replace trajectory failed return is identical to the new trajectory failed return

8.4.4Replace Trajectory AcknowlEdged Return (CM  UM)

The replace trajectory acknowledged return is identical to the new trajectory acknowledged return.

8.4.5UM Requirements for REPLACE Trajectory Operation

47000 / UM must check that the invocation conform to all Data Entity Composition and Relationship Requirements when issuing a replace trajectory invocation.
47001 / To be completed

8.4.6CM Requirements for replace Trajectory Operation

47100 / CM must validate that the replace trajectory invocation conforms to the Data Entity Composition and Relationship Requirements. CM shall reject a replace trajectory invocation that does not meet this criterion.
47101 / If a replace trajectory invocation is rejected, CM shall return replace trajectory failed to UM, identifying at least one of the invalid entities and its reason for invalidity. CM should identify as many invalid entities and accompanying reasons as possible.
47102 / To be completed

8.5Delete Carrier Profile OperaTION

The delete trajectory operation shall be supported by invocation and return interactions. Figure 8.6 illustrates the delete carrier profile operation activities of UM and CM

8.5.1Delete Trajectory Invocation (UM  CM)

The delete trajectory invocation comprises:

trajectoryRef

8.5.2Delete Trajectory Successful Return (CM  UM)

The new trajectory successful return comprises:

8.5.3Delete Trajectory Failed Return (CM  UM)

The delete trajectory failed return comprises:

Attribute # / Attribute Name / Attribute Definition/Description / Data Type / Units
41100 / trajectoryRef / Unique identifier of the trajectory as supplied by the CM in a trajectory return. / String / N/A
41310 / erredItem / Is this the same as 41210? / String / N/A
41311 / additionalInformation / Is this the same as 41211? / String / N/A
41312 / diagnostic / Specific to deleteTrajectoryReturn / String / N/A

8.5.4Delete Trajectory AcknowlEdged Return (CM  UM)

The delete trajectory acknowledged return is identical to the new trajectory acknowledged return.

8.5.5UM Requirements for DELETE Trajectory Operation

48000 / UM must check that the invocation conform to all Data Entity Composition and Relationship Requirements when issuing a delete trajectory invocation.
48001 / To be completed

8.5.6CM Requirements for delete Trajectory Operation

48100 / CM must validate that the delete trajectory invocation conforms to the Data Entity Composition and Relationship Requirements. CM shall reject a delete trajectory invocation that does not meet this criterion.
48101 / If a delete trajectory invocation is rejected, CM shall return delete trajectory failed to UM, identifying at least one of the invalid entities and its reason for invalidity. CM should identify as many invalid entities and accompanying reasons as possible.
48102 / To be completed

8.6Query Trajectory OperaTION

The query trajectory operation shall be supported by invocation and return interactions. Figure 8.7 illustrates the query carrier profile operation activities of UM and CM

8.6.1Query Trajectory Invocation (UM  CM)

The query trajectory invocation comprises:

trajectoryRef

8.6.2Query Trajectory Successful Return (CM  UM)

The query trajectory return comprises:

All attributes in [41000] except trajectoryId and serviceAgreementId

Either all attributes in [42000] or [43000], as appropriate to the queried trajectory

All attributes in [44000]

8.6.3Query Trajectory Failed Return (CM  UM)

The query trajectory failed return comprises:

Attribute # / Attribute Name / Attribute Definition/Description / Data Type / Units
41100 / trajectoryRef / Unique identifier of the trajectory as supplied by the CM in a trajectory return. / String / N/A
41410 / erredItem / Is this the same as 41210? / String / N/A
41411 / additionalInformation / Is this the same as 41211? / String / N/A
41412 / diagnostic / Specific to queryTrajectoryReturn / String / N/A

8.6.4UM Requirements for query Trajectory Operation

49000 / UM must check that the invocation conform to all Data Entity Composition and Relationship Requirements when issuing a new trajectory invocation.
49001 / To be completed

8.6.5CM Requirements for query Trajectory Operation

49100 / CM must validate that the query trajectory invocation conforms to the Data Entity Composition and Relationship Requirements. CM shall reject a query trajectory invocation that does not meet this criterion.
49101 / If a query trajectory invocation is rejected, CM shall return query trajectory failed to UM, identifying at least one of the invalid entities and its reason for invalidity. CM should identify as many invalid entities and accompanying reasons as possible.
49102 / To be completed

Figure 8.4: New Trajectory Activity Diagram (View 40003)

Figure 8.5: Replace Trajectory Activity Diagram (View 40004)

Figure 8.6: Delete Trajectory Activity Diagram (View 40005)

Figure 8.7: Query Trajectory Activity Diagram (View 40006)

[HK1]1 This assumes a series of state vectors will be provided in the message.

[HK2]1 This assumes a series of state vectors will be provided in the message.