Sheet 1

1
STEP for Space Applications -TAS and NRF
Development

• Hans Peter de Koning (ESA/ESTEC
  D/TOS-MCV)hdekonin_at_estec.esa.int
• Eric Lebègue (SIMULOG)Eric.Lebegue_at_esprico.fr

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Topics of this presentation
STEP-NRF Network-model Results Format Application
Protocol
STEP-TAS Thermal Analysis for Space
Application Protocol

• Overview of Application Protocols
• Current status of implementations
• Brief demo with ESARAD
• STEP-TAS Converter Development Toolkit

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NRF and TAS main documents
Definition and Results of Analyses, Tests
Operations Integrated Application Resource
Space Domain Integrated Application Resource
Thermal Analysis Integrated Application
Resource
STEP-NRF Network-model Results Format Application
Protocol
STEP-TAS Thermal Analysis for Space Application
Protocol
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Application Reference Model Units of
Functionality
TAS space_mission_aspects geometric_model kinema
tic_model thermal_radiative_model visual_presentat
ion material_properties additional_physical_quanti
ties_and_measures
NRF product_structure network_model_representation
bulk_results parameterized_functions date_and_tim
e general_support
The ARM is organised in UoFs UoFs are collections
of application objects and their relationships
specified in the terminology of the application
domain
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Main characteristics of NRF (1)

• Generic discipline-independent protocol
• Scope is definition and representation of
• engineering objects represented by a
  network-model of discrete nodes and relationships
  between the nodes -network-model may contain a
  submodel hierarchy
• representation of properties of engineering
  objects for which result values can be predicted
  / observed at discrete states
• analysis, test or operational campaigns / cases /
  phases
• analysis, test or operational runs with
  associated results
• product structure compliant with AP203 CC1 / PDM
  schema
• relationships between product structure and
  network-model

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Main characteristics of NRF (2)

• Results are properties with value and unit
• Descriptive values (text string, item from
  enumerated list)
• Numerical values (scalar, vector, tensor)
• Parameterised function values (tabular
  interpolation, polynomial, limited expressions)
• NRF protocol has two separate parts
• Static protocol, discipline-independent data
  structures
• Dictionairies defining node and node-relationship
  classes, properties, property-qualifiers,
  property-value-range, ...
• Purpose of dictionairies is to enable flexible /
  adaptable use without need to re-issue the
  standard

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Main characteristics of NRF (3)

• Great care is taken to define light, efficient
  data structures
• Sparsely populated results value space
• Properties only one kind of unit in a data set
• Starting on development of a best of both
  worlds solution
• NRF for semantics
• HDF5 for efficient binary portable implementation
  method (HDF Hierarchical Data Format by NCSA)

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Main characteristics of TAS (1)

• Self contained, complete Application Protocol
• AAM, ARM, Mapping Table, AIM, Express-G (586
  pages)
• Conforms to TC184/SC4 methods and guidelines
• Geometry defined as AP203 CC4 surfaces
• Thermal-radiative model faces added as associated
  features
• Including possibility to support hierarchical
  submodel tree
• Associated notional thickness, surface material
  and bulk material
• Thermo-optical, thermo-physical properties for
  named material
• Concept of material property environment (Part
  45)
• Kinematic model conform STEP Part 105 for
  articulating rigid bodies (e.g. rotating solar
  arrays, gimballed antennas)

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Main characteristics of TAS (2)

• Space mission aspects
• orbit arc (Keplerian and discrete ephemeris)
• space co-ordinate system, celestial bodies
• orientation, general and named pointing,
  spinning, linear rotation rates
• space thermal environment, including constant or
  lat/long dependent albedo / planetshine tables
• Boolean construction surfaces available for
  advanced tools
• STEP-TAS CC1 Abstract Test Suite
• conform STEP Part 3xx series
• test suite has been used in validation of TAS
  processors

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TAS geometry and thermal-radiative models

• Shapes
• Primitives triangle, rectangle, quadrilateral,
  disc, cylinder, cone, sphere, paraboloid
• Compound shapes
• Shapes conform to AP203 CC4 non-manifold surfaces
• Thermal-radiative model
• associates thermal-radiative faces with surface
  shapes
• thermal mesh
• surface and bulk material

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Illustration of basic TAS Keplerian orbit
definition
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STEP-TAS Conformance Classes
thermal-radiative model with basic geometry
kinematic model
constructive geometry
space mission aspects
CC-1
?
CC-2
?
?
CC-3
?
?
CC-4
?
?
?
CC-5
?
?
?
CC-6
?
?
?
?
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STEP-NRF implementation status

• Read/write library available with C and FORTRAN
  binding
• Prototypes produced with CNES and Electricité de
  France
• Being prepared for use in ESAs next generation
  integrated thermal analysis tool code-named
  Polytan as an open post-processing interface

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STEP-TAS Implementation Status

• Read/write libraries available with C and FORTRAN
  bindings
• Including programming tutorials / manuals (HTML
  and PDF)
• Ported and verified on 5 platforms PC/Windows,
  Sun/Solaris, HP/HP-UX, Compaq-Dec/Tru64, SGI/Irix
• High level interface layer included at ARM/user
  domain level Provides very significant savings
  in processor development effort
• Working processors
• CC1 processor in ESARAD 4.1.x (released summer
  1999)
• CC1 processor in THERMICA release April 2000
• Currently large model cross validation ESARAD -
  THERMICA
• Proof-of-concept prototypes developed with
  NASA-JPL for TRASYS and TSS (1998)

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ROSETTA in ESARAD
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ROSETTA in Baghera View
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ROSETTA in THERMICA
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Doris in THERMICA
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Doris in Baghera View
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DORIS in ESARAD
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Mars Rover in TSS
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Mars Rover in Baghera View
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Mars Rover in ESARAD
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Mars Rover in THERMICA
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STEP-TAS future

• STEP-TAS Processor Development Kit available to
  thermal analysis tool vendors
• From SIMULOG at nominal cost EURO/USD 1000
  (Jan-2000) Including initial e-mail tech-support
• Baghera View is available in addition (Contact
  Eric Lebègue)
• ESA is considering proposing STEP-TAS to ISO
  TC184/SC4
• New Work Item leading to new ISO 10303 part
• Continue large model cross-validation and
  performance tuning
• Initiate support for other conformance classes