CHORUS Project: MBSE reduces risk and increases success in developing complex cross-disciplinary designs



High data rate communications to and from small aperture satellite earth terminals are reaching the limits of Radio Frequency (RF) technology.

Furthermore, current generation military communications are vulnerable to electronic warfare and this is likely to further degrade in the future unless new approaches to the provision of communications are developed.

Defence Science and Technology Group (DSTG) are working with SmartSat Cooperative Research Centre (CRC) to address these problems by employing a cross-disciplinary team to create innovative technology options. This collaboration has the potential to create new market opportunities for Australian industry and to address Australia’s need for sovereign space capabilities.

The Compact Hybrid Optical-RF User Segment (CHORUS) Project aims to assess the technical viability of a small aperture, combined hybrid Optical-RF terminal. CHORUS aims to exploit diversity in electromagnetic wave propagation to provide a secure, high data rate and high availability satellite link from a single low-cost terminal.

The CHORUS team is a geographically dispersed group of experts from industry and academia working for multiple organisations. Finding efficient ways to collaborate and share information is essential to success in this project.


Shoal is an important part of this team, providing necessary contributions to the project. Shoal is contributing our systems engineering capabilities to support the R&D of the communication terminal, and using Model-based Systems Engineering (MBSE) to capture the system design and improve design analysis and decision making. This MBSE model represents a ‘digital twin’ of the emerging communication concept being researched.

Shoal is applying MBSE methods and tools to help guide and expedite the research and development effort on CHORUS. By developing and maintaining a ‘digital twin’ of the system under investigation in an MBSE environment, optimisation and design trade studies can occur concurrently with research activities. The digital twin maintains a single source of truth accessible to all stakeholders and an audit trail of decision points and rationale.

This iterative approach allows faster development and enables a nuanced approach to risk management in what is acknowledged to be a high-risk activity. It should also reduce long term costs should the project enter technology demonstration and prototyping phases.

This approach constitutes a test case for other SmartSat CRC projects to understand the interplay between digital engineering, systems engineering, technology development and project management within research and development projects across all facets of space systems and services.


So far, the MBSE approach and ‘digital twin’ are:

  • Providing a common engineering framework for design trade-offs and decisions to be across the technical disciplines of the solution concept
  • Resulting in a reusable template for specifying future iterations and variants of the CHORUS terminal, as well as a specification for interfacing systems, such as the modem(s) and satellite terminal(s)
  • Providing an audit trail of decision-making and rationale for selections made as the R&D effort proceeds
  • Facilitating information exchange within the team by acting as a ‘single source of truth’ accessible to all stakeholders
  • Collecting the verification evidence providing answers to the study questions driving the R&D activity.

Preliminary feedback from within the project team suggests that the MBSE-based approach has streamlined the feasibility study phase of Project CHORUS and helped the team rapidly and effectively arrive at a set of configurations to take into prototyping.

The ‘digital twin’ will continue to evolve through the research and development lifecycle and support the adoption of the technology into operational use.

Image: EOS Solutions