Prototyping operational autonomy for Space Traffic Management

摘要

Current state of the art in Space Traffic Management (STM) relies on a handful of providers for surveillance and collision prediction, and manual coordination between operators. Neither is scalable to support the expected 10x increase in active spacecraft population in less than 10 years, nor does it support automated maneuver planning. We present a software prototype of an STM architecture based on open Application Programming Interfaces (APIs), and drawing on insights from NASA's architecture for low-altitude Unmanned Aerial System Traffic Management. The STM architecture is designed to provide structure to the interactions between spacecraft operators, various regulatory bodies, and STM service suppliers, while maintaining flexibility of these interactions and the ability for new market participants to enter easily. Autonomy will be an indispensable part of the proposed architecture in enabling efficient data sharing, coordination between STM participants and safe flight operations (e.g. select spacecraft maneuvers to prevent impending conjunctions between multiple spacecraft).The STM prototype is based on modern micro-service architecture adhering to OpenAPI standards and deployed in industry-standard virtualized containers, facilitating easy communication between different participants or services. The system architecture is designed to facilitate adding and replacing services with minimal disruption. We have implemented some example participant services (e.g. a space situational awareness/SSA provider, a conjunction assessment supplier/CAS, an automated maneuver advisor/AMA) within the prototype. Different services, with creative algorithms folded into them, can fulfill similar functional roles within the STM architecture by flexibly connecting to it using pre-defined APIs and data models, thereby lowering the barrier to entry of new players in the STM marketplace.We demonstrate the STM prototype on a multiple conjunction scenario with multiple maneuverable spacecraft, where an example CAS and AMA can recommend optimal maneuvers to the spacecraft operators, based on a pre-defined reward function. Such tools can intelligently search the space of potential collision avoidance maneuvers with varying parameters like lead time and propellant usage, to optimize a customized reward function, and be implemented as a scheduling service within the STM architecture. The case study shows an example of autonomous maneuver planning using the API-based framework. As satellite populations and predicted conjunctions increase, an STM architecture can facilitate seamless information exchange related to collision prediction and mitigation among various service applications on different platforms and servers. The availability of such an STM network also opens up new research topics on satellite maneuver planning, scheduling and negotiation across disjoint entities.