Demonstrating Interoperability Between Heterogeneous Simulation Platforms via Hyperspace Modeling Language

The increasing activity in lunar exploration, particularly around the Lunar South Pole, abundant in resources, highlights the urgent need for collaboration and interoperability between diverse stakeholders. Digital twins (DTs) have emerged as a powerful tool to support coordination, decision-making, and mission reliability, yet current implementations remain fragmented, relying on proprietary tools and lacking standard interfaces. The IEEE 2874-2025 Spatial Web standard addresses these gaps through protocols such as the Hyperspace Modeling Language (HSML) and Hyperspace Transaction Protocol (HSTP), which aim to enable seamless, secure, and decentralized data exchange across heterogeneous platforms. This study evaluates the effectiveness of HSML and HSTP for digital twin interoperability in a lunar rover assistance use case simulated in Unity and NVIDIA Omniverse Isaac Sim. A verification framework was developed using the DID:key method for identity management, a MySQL registry for credential validation, and a RESTful HSML API for authenticated and authorized communication over Kafka. Results show real-time synchronization with latency well below human reaction time, confirming the feasibility of trusted, crossplatform interactions. These findings demonstrate the potential of the Spatial Web as a foundation for future collaborative space missions.