In the second article of this series, we looked ahead to the Model-Based Space Systems and Software Engineering (MBSE 2025) workshop, held from 5 to 7 November 2025 in Vilnius, Lithuania. The workshop brought together representatives from industry, space agencies, academia and tool vendors to exchange ideas and experiences on the present and future of model-based systems engineering (MBSE) in the space sector, with SysML v2 being one of its central themes.
Here, we look back at the outcomes of the event, with a particular focus on the SysML v2 Hackathon. We explain how Starion developed a capability to export requirement specifications from a SysML v2 model to a ReqIF file, allowing them to be re-imported at a later stage. We also share the key insights and lessons learned from working with SysML v2 during the hackathon, drawing not only on our own experience but also on the presentations and discussions with other participants.
By Jaap Jannsen, Consultant MBSE Engineer
The SysML v2 Hackathon
For the hackathon, the European Space Agency (ESA) prepared an open-source SysML v2 reference model based on the ESA Concurrent Design Facility (CDF) feasibility study of the COMET Interceptor mission: a future ESA science mission targeting a long-period comet or interstellar object.
Ahead of the event, participating teams had outlined the modelling capabilities they intended to develop or evaluate using this reference model, enabling focused and parallel contributions during the hackathon. These ranged from API usage, requirements exchange and model quality analysis to the integration of engineering disciplines, life cycle and mass and power budgets, design variants, simulation, validation and interoperability with ontologies, and operational procedures.
Collectively, these contributions were not intended to demonstrate everything that SysML v2 can do, but rather to explore how the language and associated tools can best support space systems engineers in their day-to-day work, providing practical capabilities to improve modelling, analysis and collaboration across complex mission architectures.
Requirements export and import capability
Being able to efficiently manage design requirements between system models and dedicated requirements management tools is critical throughout the entire engineering lifecycle, from defining requirements in the early design phases to verification and validation at later stages. To address this need, the Starion team developed a requirements export and import capability for SysML v2 models.
This capability allows users to export any requirement defined in a SysML v2 model into a ReqIF file, which can then be imported, reviewed and modified using any ReqIF-compatible requirements management tool. Once changes are made, the capability seamlessly imports the modified ReqIF file back into the SysML v2 model’s textual notation, updating the model with the revised specifications.
To implement this functionality, we leveraged Sensmetry’s SysIDE Automator, a Python API that provides programmatic access to SysML v2 models. The API was used not only to read and write model data but also to deserialise JSON-serialised SysML v2 models into textual notation, ensuring smooth integration with the ReqIF workflow.
The capability was tested and verified using the MBSE tool Capella. This is not a dedicated requirements management system but it supports ReqIF import and modification, demonstrating the potential of this workflow for improving interoperability between SysMLv2 models and external requirements tools (see figure below).
Mapping SysML v2 to ReqIF (XML)
To provide a more detailed view of the requirements export and import workflow, it’s important to understand how SysML v2 requirement specification objects are mapped to the standard ReqIF structure.
Each SysML v2 requirement that is defined with attributes such as ID, text, rationale and relationships is translated into corresponding elements within the ReqIF format. This ensures that all essential information is preserved during export and can be correctly re-imported. The table below illustrates this mapping process to show how different SysML v2 objects are handled within the ReqIF format:
Any package in SysML v2 that contains requirements is treated as a SPECIFICATION in ReqIF by the developed ReqIF import and export capability. The SPECIFICATION-TYPE is named ‘Specification’ by default, since SysML v2 does not allow package definitions.
Requirement definitions are not mandatory in SysML v2 but in ReqIF format a SPEC-OBJECT-TYPE must be defined. Therefore, if no requirement definitions are present in the SysML v2 model, a package ‘SPEC_OBJECT_TYPES’ with a requirement definition ‘Requirement’ will be generated. If the model contains nested requirement objects, a requirement definition ‘Chapter’ will be generated as well.
Both ‘doc’ and ‘comment’ are attributes in SysML v2 that are mapped to ATTRIBUTE-VALUE-STRINGs in ReqIF of ATTRIBUTE-DEFINITION-STRING ‘ReqIF.Text’ and ‘Comment’ respectively.
Lastly, in SysML v2 a metadata definition ‘derivation’ can be imported from the ‘RequirementDerivation’ library to define a derivation-type connection. This is mapped to a SPEC-RELATION-TYPE in ReqIF.
The figure below shows a SysML v2 code example with corresponding ReqIF mappings.
Key insights and lessons from the hackathon
Sharing the results of all hackathon participants during the MBSE 2025 workshop in Vilnius provided valuable insights into the current state of SysML v2 and its tooling environment, as well as opportunities for its future development:
- Setup: Installing and configuring the tools and modelling environments is feasible, even for those without a software development background, but it requires time and attention. Unlike traditional software, it’s not simply a matter of running an installer. Some initial complexity may discourage newcomers.
- Tooling maturity: SysML v2 tools are still evolving and users should expect bugs or incomplete feature sets. Examples include limited support for parameter units or importing namespaces from external sources, which are not yet fully implemented across current tools.
- Potential of combined textual and diagram-based modelling: While visual diagrams remain important for understanding and communicating system models, the textual modelling capabilities in SysML v2 are likely to be transformative. They promise to increase modelling speed and pave the way for AI-assisted system design, enabling more efficient, precise, and automated workflows in the future.
Summary
The MBSE 2025 SysML v2 Hackathon demonstrated the value of collaboration, experimentation and practical tool integration in advancing MBSE for space missions. By developing capabilities on top of ESA’s COMET Interceptor reference model, participants were able to explore how SysML v2 can directly support the work of space systems engineers, improving interoperability, traceability and efficiency across complex projects.
Beyond the technical achievements, the hackathon highlighted the current state and potential of SysML v2 tooling, offering hands-on experience with multiple vendor implementations and revealing opportunities for future development.
As SysML v2 continues to mature, initiatives like this hackathon provide a blueprint for the broader MBSE community to experiment, collaborate and shape practical, engineer-focused solutions, ensuring that the language and tools evolve in ways that meet the real needs of system engineers, today and tomorrow.
Do you want to learn more?
If your team or organisation is interested in MBSE, if you would like to learn more about SysML v2 to implement it in your projects, or if you simply work on the space sector and want to stay up to date with the latest digital developments that will set the course for future missions, follow Starion on LinkedIn and sign up to our SysML v2 and MBSE newsletter. Now is the perfect time to start exploring SysML v2, test out new tools and define transition plans to adopt the new version in your modelling activities.
You can also reach out to our team for guidance and support.
