Data Exchange and MBSE Developments for Space Hans Peter de Koning (ESA/ESTEC, Noordwijk, The Netherlands) Harald Eisenmann (EADS/Astrium Satellites, Friedrichshafen, Germany) 11th NASA-ESA Workshop on Product Data Exchange 29 April - 1 May 2009

Intergovernmental organisation European Space Agency Intergovernmental organisation 18 member states Annual budget around 3 billion € Approximately 2000 staff http://www.esa.int 11th NASA-ESA Workshop on Product Data Exchange 29 April - 1 May 2009

Moving towards Model Based Systems Engineering Topics Moving towards Model Based Systems Engineering Standardization INCOSE & OMG: SysML ECSS: "Engineering Database" ... R & D Studies to validate standardization approach Virtual Spacecraft Design Space Thermal Analysis Model Exchange Status STEP-TAS implementations Geometrical models and space mission apects Thermal test results New development Conversion between ESATAN, SINDA/FLUINT, SINDA/G 11th NASA-ESA Workshop on Product Data Exchange 29 April - 1 May 2009

What is Model Based Systems Engineering? (INCOSE definition) Model-based systems engineering (MBSE) is the formalized application of modeling to support system requirements, design, analysis, verification and validation activities beginning in the conceptual design phase and continuing throughout development and later life cycle phases "INCOSE SE Vision 2020" INCOSE-TP-2004-004-02 Sep 2007 11th NASA-ESA Workshop on Product Data Exchange 29 April - 1 May 2009

European space industry Current approach and status Space system development process Overall system engineering process well established – applied on all ESA projects Standard: ECSS-E-ST-10-1C "System engineering general requirements" All domain (discipline-specific) processes are well established – applied on all ESA projects Avionics, power, structures, mechanisms, thermal control, propulsion, optics, software (on-board, groundstation), communication, control (orbit & attitude, robotics), Project management, cost, risk, logistics, product assurance, … Each with own ECSS standard Tools Domain disciplines are well supported in terms of engineering and analysis tools For some disciplines there is excellent integration of design and analysis tools Lack of support for system engineering: System level design is typically defined with office tools System level design is “scattered” in different tools – with little traceability 11th NASA-ESA Workshop on Product Data Exchange 29 April - 1 May 2009

Industrial Practice Limited Model Based Capabilities Current industrial practice: Many elaborated tools (analysis) and databases in use Pragmatic bottom-up integration of particular tool chains Many ad hoc databases System level design status – by system modeling Very good representation in phase 0/A (parametric models – standardized set of properties) Requirements specifications partly in databases (RE Tools), partly in documents, some traceability Very good representation for some disciplines (e.g. MCAD) Phase B representation often kept in MS-Office products System modeling is often driven bottom-up (e.g. flight software or simulation) 11th NASA-ESA Workshop on Product Data Exchange 29 April - 1 May 2009

Trend: System Engineering "V" with Model-based Validation & Verification Mission Need Phase A Phase B Phase C Phase D Phase E Feasibility Study Conceptual Design System / Preliminary Design Detailed Design Manufacturing Assembly Integration Verification Deployment Validation Top-Down Design Bottom-Up Production, V&V (Development & Qualification) Early V&V Early V&V Executable Model-based Validation & Verification 11th NASA-ESA Workshop on Product Data Exchange 29 April - 1 May 2009

Model Based (System) Engineering Expected benefits Systematic application of models for specification, design, verification and validation Both for structure and behavior of the system Managed traceability between all aspects and integrated version/configuration control Expected benefits of consistent application of models As much as possible single source data – generate/transform where possible Allows computer aided completeness, consistency and quality checking Improved collaboration between disciplines and organisations Multidisciplinary teams Efficient and reliable communication through supply chain Eases development iterations and change impact analysis Enables and promotes knowledge capture and (re-)use Enables multiple, concurrent views (subsets, presentations) on same data Reduced “manual” work and thus improve cost, schedule and quality / reduce risk 11th NASA-ESA Workshop on Product Data Exchange 29 April - 1 May 2009

Comprehensive system level design representation Ultimate Goal – MBSE Comprehensive system level design representation Seamless data traceability from system level design into domain engineering design Consistent “transformation” from system design model into analysis (executable) model For domain analysis models System simulators Consistent representation of the decision making process (analysis  design  verification) Continuous verification / validation based on consistent application of virtual models 11th NASA-ESA Workshop on Product Data Exchange 29 April - 1 May 2009

Enabling Technologies Overall Integration Framework required For efficient tool integration For data exchange and sharing To ensure common and mappable semantics Specification of the required data In a formal way on a conceptual level – ref. OMG/MDA PIM (Platform Independent Model) Enabling subsequent “generation” of required implementation technology System level design editors Definition, modification and presentation of engineering data Capturing properties and values Supported by open standards Cannot and want not standardize on tools 11th NASA-ESA Workshop on Product Data Exchange 29 April - 1 May 2009

Supporting standardization and R&D ECSS-E-TM-10-23 "Engineering Database" Technical Memorandum evolving to a future standard Conceptual data model defining precise common semantics MBSE reference architecture – using OMG/MDA principles Re-use from STEP-NRF: formalized representation of quantities, units, dimensions, … As much as possible aligned with SysML ESA funded R&D Space System Reference Model Prototyping of centralized services as integration platform – validation of E-TM-10-23 Virtual Spacecraft Design Demonstration of a space system engineering process relying on a virtual representation Design Resource Center Design data library to ease access 11th NASA-ESA Workshop on Product Data Exchange 29 April - 1 May 2009

ECSS = European Cooperation for Space Standardization Initiative started in 1995 to produce a coherent, single set of user-friendly standards for use in all European space activities Previously there were different ESA and national space standards Partners are space industry (via the Eurospace association), ESA and national space agencies Published standards freely available from http://www.ecss.nl in PDF (after a simple registration procedure) Complete update per March 2009 11th NASA-ESA Workshop on Product Data Exchange 29 April - 1 May 2009

ECSS E-TM-10-23 "Engineering database" Conceptual data model standard Purpose: to provide common semantic reference for all engineering data repositories needed to develop and operate a space system through the whole life cycle Defined using UML2 (class diagram) Looking at simultaneous specification in ontology language (OWL, ORM) and EXPRESS First release imminent Expected May/June 2009 Will be published in hyperlinked wiki form to allow efficient review and evolution (generated from OpenAMEOS UML tool) 11th NASA-ESA Workshop on Product Data Exchange 29 April - 1 May 2009

ECSS E-TM-10-23 "Engineering database" 11th NASA-ESA Workshop on Product Data Exchange 29 April - 1 May 2009

ECSS E-TM-10-23 Adoption of the ECSS global conceptual data model for a project 11th NASA-ESA Workshop on Product Data Exchange 29 April - 1 May 2009

Aligned with E-TM-10-23 (subset) Agreed list of reference data ECSS E-TM-10-25 ESTEC CDF Technical Memorandum to agree the exchange of conceptual design models (Phase 0 / A) between concurrent design facilities Aligned with E-TM-10-23 (subset) Agreed list of reference data List of design parameters with responsible discipline (~600 parameters) List of recognised disciplines Basic system decomposition First release expected May/June 2009 Supported by OCDS (Open Concurrent Design Server) replacing Excel based infrastructure 11th NASA-ESA Workshop on Product Data Exchange 29 April - 1 May 2009

Space System Reference Model Integration Platform SSRM Tool Connectors SSRDB Connector SSRM Database SSRM Tools ATV Tools ATV SSRM Control WS Engineering WS Business Logic Basic S y s t e m E n g i r C o l G U I Prototype an architecture on the SOA principles providing Dedicated tool integration adaptors Data management ‘procedures’ DB adapter to a RDBMS Validate the approach on how ETM-10-23A model is defined with respect to Evaluation of data modeling techniques Comparison to existing data models (i.e. STEP AP’s) Adequacy of data model to facilitate MDA development process Develop and demonstrate a prototype with an industrial scenario 11th NASA-ESA Workshop on Product Data Exchange 29 April - 1 May 2009

Space System Reference Model Objective Prototype physical and semantic integration platform Validation of draft E-TM-10-23 data model w.r.t. STEP, MDA compatibility Demonstration based on real industrial scenarios Result Centralized webserver hosts shared applications like: adaptors, core application, version control, … Persistent storage of data in RDBMS Control applications MDA based development framework Status Study successfully finished in May 2008 Results will be evolved in Virtual Spacecraft Design Prototype an architecture on the SOA principles providing Dedicated tool integration adaptors Data management ‘procedures’ DB adapter to a RDBMS Validate the approach on how ETM-10-23A model is defined with respect to Evaluation of data modeling techniques Comparison to existing data models (i.e. STEP AP’s) Adequacy of data model to facilitate MDA development process Develop and demonstrate a prototype with an industrial scenario 11th NASA-ESA Workshop on Product Data Exchange 29 April - 1 May 2009

Design Resource Center Objective Development of design data library Definition of equipment properties (used for design) Result Web-server application for the core application HTML front-end integrated in ESA portal Underlying relational database Linkage to ESA DMS 11th NASA-ESA Workshop on Product Data Exchange 29 April - 1 May 2009

Virtual Spacecraft Design Objectives Demonstration of a model-based system engineering process using a full virtual representation of the space system Status - End phase 1 Requirements analysis and conceptual design Overall process analysis performed Use case analysis and user requirements specification performed Overall architecture defined  lower level elements identified for prototyping Next step – Phase 2 realization and demonstration (2009 – 2010) Space System Design Editor Space System Reference Database Space System Visualization Tool Builds further on E-TM-10-23, SSRM centralized integration platform, MDA for design editors, STEP-NRF 11th NASA-ESA Workshop on Product Data Exchange 29 April - 1 May 2009

Virtual Spacecraft Design 11th NASA-ESA Workshop on Product Data Exchange 29 April - 1 May 2009

Space System Engineering Repository Overview Data Bases Input by domain Administrators Handling of Data via Eng. Tool Supplier ASTRIUM S/C Eng. Reference Customer Space System Engineering Repository SEDB SDB (TM/TC) MCAD DB (CAD Model) CC DB = SCC DB EPPD Equip. Physical Props. SRDB MCAD Tool: CATIA ECAD Tool: Eng. Base SimDB Tool: SimDB SCOE TM/TC DB AP DB Tool: MOIS FDDB Unit/ Equipment-SDB AIT SDB OBSW SDE AOCS OSE Tool: Matlab/ Simulink Parts/ Struct./ Harness Manufact. El.Test Tool Tool: IDAS IDAS DB Control Console Tool: SimOps/ OpenCenter EGSE DB MDVE Simulator EGSE DB 11th NASA-ESA Workshop on Product Data Exchange 29 April - 1 May 2009 Development & Verification Tools

Example validation of E-TM-10-23 in prototype space system design editor Eclipse (Ganymede) based tool Using GMF and EMF Code generated from E-TM-10-23 data model using MDA approach Developed by ScopeSET (Germany) 11th NASA-ESA Workshop on Product Data Exchange 29 April - 1 May 2009

Example validation of E-TM-10-23 in prototype space system design editor 11th NASA-ESA Workshop on Product Data Exchange 29 April - 1 May 2009

Support SysML RTF 1.2 and 2.0 work through INCOSE/OMG Support to SysML Support SysML RTF 1.2 and 2.0 work through INCOSE/OMG Upgrade of Quantities, Units and Dimensions – foundation for SysML "value properties" Now based on International Vocabulary of Metrology by BIPM Combined concepts and lessons learned from ISO 10303-41, STEP-NRF, MARTE, ontologies Fully supports multiple quantities and units systems Using new ISO/IEC 80000 standard (harmonised replacement of SI) as main reference Integration of SysML Parametrics and Modelica Modelica is a neutral language to define object oriented non-causal simulation models see http://www.modelica.org Powerful definition of executable (high level to detailed) system models Mathematical equations relating properties at ports of blocks With or without predefined causality (order of variable assignment or expression evaluation) Fits well with SysML contraint blocks 11th NASA-ESA Workshop on Product Data Exchange 29 April - 1 May 2009

STEP-TAS progress 11th NASA-ESA Workshop on Product Data Exchange 29 April - 1 May 2009

STEP-TAS Activities in 2008 IITAS – Industrial Implementation of STEP-TAS – in progress ESA completed full test suite with automation tools TASverter by ESA TEC-MTV (Thermal analysis and verification section) Now more than 150 different users (2~5 downloads per week) Routine use in many projects Under maintenance – but very few bugs reported Evolution of Expressik to support code generators STEP EXPRESS to C++ and Python Evolution mapping STEP data into HDF5 format Completed ESATAP v1 thermal analysis post-processor using STEP-TAS in HDF5 format First validation of STEP-TAS Kinematics and Mission Aspects (CC2, CC4, CC5, CC6) Implementation in TASverter for ESARAD Proof of concept implementation in DynaWorks® for import of STEP-TAS analysis predictions 11th NASA-ESA Workshop on Product Data Exchange 29 April - 1 May 2009

Started IITAS-TMG activity with Maya (Canada) In progress 2009 Started IITAS-TMG activity with Maya (Canada) Implementation of STEP-TAS import/export into TMG Completion of IITAS and IITAS-TMG Emphasis on testing and obtaining robustness of imports/exports Full validation of STEP-TAS Kinematics and Mission Aspects Implementation of full ESATAN / SINDA conversion in STEP-TAS and TASverter Formalisation of STEP-NRF/TAS under ISO TC184/SC4 Was planned for 2008 but put on-hold due to lack of resources – shifted to 2009 R&D "Innovative methods for improved thermal testing" o.a. using STEP-TAS to interface between analysis prediction and test results Consolidate support software and test suites as true open source software Depending on ESA open source software policy that is currently being finalised 11th NASA-ESA Workshop on Product Data Exchange 29 April - 1 May 2009

ESATAN / SINDA conversion using STEP-TAS ESATAN, SINDA/FLUINT, SINDA/G are major space thermal analysis tools Old style FORTRAN finite difference / lumped parameter solvers Common heritage to CINDA which was developed in 1960s Used on many space projects worldwide Model defined in two parts: DATA and OPERATION blocks DATA blocks define model structure: nodes, conductors, boundary and initial conditions, ... OPERATION blocks define behaviour simulation: user defined logic and solver calls Quite sophisticated modelling capabilities for active thermal control: thermostats, PID controllers, heatpipes, fluid loops, evaporators/condensors, Peltier elements, mission (power) mode switching, model parameterization, non-linear material properties, ... Exchange of DATA blocks is supported by existing tool-to-tool converters But incomplete and not reliable Exchange of OPERATION blocks is manual: very complicated and time consuming 11th NASA-ESA Workshop on Product Data Exchange 29 April - 1 May 2009

Data exchange implementation ESATAN / SINDA OPERATION blocks ANTLR (http://www.antlr.org) is a very powerful OSS lexer/parser package. JSON (http://www.json.org) is JavaScript Object Notation, a very powerful but simple serialization format supported by OSS in almost all programming languages. Use ANTLR to parse ESATAN or SINDA MORTRAN language Store resulting abstract syntax tree in prefix notation using JSON For expressions we use the Content MathML approach Only not in XML but JSON encoding e.g. "X = 4.0 * (2.0 + 3.5)" → ["assign", "X", ["times", 4.0, ["plus", 2.0, 3.5]]] For algorithms (sequence of statements, if-elseif-else blocks, loops, etc.) we use simple keywords e.g. ["loop_for", loop_var, start_expression, end_expression, step_expression, statement_block] Integrated into STEP-TAS through EXPRESS ENTITY instances nrf_algorithmic_language, nrf_algorithmic_expression, nrf_algorithmic_statement Both in neutral JSON language and original ESATAN or SINDA language Prototypes work very well Perhaps interesting light approach also for other algorithm conversion need Upgrade of TASverter expected later this year Development contracted to DOREA (France) 11th NASA-ESA Workshop on Product Data Exchange 29 April - 1 May 2009

European Space Agency http://www.esa.int References European Space Agency http://www.esa.int Astrium Satellites http://www.astrium.eads.net European Cooperation for Space Standardization http://www.ecss.nl SysML – Systems Modeling Language http://www.omg.sysml.org STEP-NRF and STEP-TAS http://www.esa.int/thermalcontrol Look for "Standards” TASverter https://exchange.esa.int Look for "TASverter“ ISO TC184 / SC4 standardization committee (a.o. STEP standards) http://www.tc184-sc4.org 11th NASA-ESA Workshop on Product Data Exchange 29 April - 1 May 2009