BESTA: Discovery of Anomalous Behavior Supporting Automated Space Traffic Management

By Harvey Reed , Nathaniel Dailey , Robert Carden , Dave Bryson

MITRE explores using blockchain to improve provenance of STM information to support automated discovery (and safeguarding evidence) of anomalies, supporting increased STM automation. An international multi-tier information sharing model is proposed.

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Today, satellite launches, on-orbit operations, and deorbiting by space faring countries is manual-intensive and safe. However, projected increases in number of space faring nations, and volume of space traffic, will strain Space Traffic Management (STM) processes and operations, requiring increased automation. STM processes and operations require timely space object data for all objects, in the context of clear and unambiguous understanding of the current agreements and intents for maneuvering and operating active space objects.

However, the volume, types, and complexity of space object data is steadily increasing, for example (a) increasing number space objects including from mega constellations; (b) increasing number of types of data beyond TLE such as intent to maneuver and health/status; (c) increasing number of sources of data from commercial and national sources, and; (d) increased need for cross-domain information sharing and integration across space, air space, land, and maritime domains. The increase in number, types, and complexity of space object agreements is driven by a growing number of spacefaring and space interested nations who enter into agreements which describe increasingly complex ranges and constraints of operational behavior. The ability to discover behavioral anomalies by comparing observed behavior to agreed and intended behavior is the foundation for encouraging good behavior and enforcing compliance.

BESTA (Blockchain Enabled Space Traffic Awareness) is a proposed framework for automatically detecting behavioral anomalies, by comparing observations to agreements, then recording the anomalies on the BESTA blockchain as evidence dockets for subsequent adjudication. This is a first step toward automating key activities of STM. BESTA compares space object data to agreements in order to detect anomalies which represent potential non-conforming space object behavior. These anomalies, together with pertinent data and agreements are captured in evidence dockets on the BESTA blockchain, for subsequent adjudication, either human in the loop, or automatic. Comparison of data and agreements requires provably correct provenance of both the space object observation and other data, and the applicable agreement documents. Further, the generated evidence docket must be protected against tampering. BESTA is an open source, permissioned blockchain-enabled capability suitable for international and commercial stakeholders, providing tamper-evident, attributed, resilient, and available data. This paper describes high level modular architecture and needed research to enable prototype implementations.

BESTA internal architecture is modular, enabling continuous evolution and improvement. Types of modules include (a) SDA Input Provenance; (b) SDA Information Sharing; (c) Agreements Provenance; (d) Agreement Information Sharing; (e) SDA and Agreement Comparison; (f) Anomaly Evidence Preparation; (g) Anomaly Adjudication. For each type of module, there may be multiple instances of module, where each instance is dedicated to a type of data, such as TLE, frequency, etc. The instance of module then uses instances of actual data at runtime.

BESTA research topics inform modules such as anomaly discovery in the SDA and Agreement Comparison module, and evidence capture and secure storage in the Anomaly Evidence Preparation module. Discovery research includes automatic ingest of agreements, policies, and regulations into machine readable ontologies for later comparison to behavior observation data streams, as well as reconciliation of multiple and perhaps differing observation data (e.g. multiple catalogs). Evidence capture and secure storage research includes automatic preparation of evidence packages which contain relevant agreements and observations, to be used in subsequent adjudication and mitigation activities. Results of discovery and evidence preparation must be trusted across all stakeholders even in contested or adversarial environments (e.g. space and great power competition). Further, BESTA must be “brownfield” that is able to be used in current context (agreements, data) with minimal disruption.

The vision for BESTA is a platform to enable safe and secure voluntary information sharing and decision making to support international cooperative STM. There are analogs to the envisioned information sharing model, such as the Aviation Safety Information Analysis and Sharing (ASIAS), and International Civil Aviation Organization (ICAO) operating models. BESTA blockchain nodes are owned and operated by participating spacefaring nations ensuring tamper-evident and attributed data with resilience and availability against accident or attack. Use of the International Space Reference Architecture (ISRA, Dailey, Reed IAC 2019) to align policy, behavior, and lexicon can assure common understanding and meaning of discovered anomalies and evidence packages.

Paper closes with a proposed information sharing model for STM that includes: (a) foundational space sensor data (e.g. Space Surveillance Network); (b) economically-driven augmentation of foundational space sensor data with commercial and academic sensor data, and; (c) use of BESTA to reconcile multiple inputs of space object data, compared to prior agreements and statements of intent, automatically detecting anomalies and recording them in evidence dockets as they occur.