CSS is a horizontally scalable streaming service that ingests position data and emits conjunction reports, within a configurable horizon, for objects on orbit or crossing orbits. Depending on resources, alerts are emitted throughout the horizon in seconds after position data arrives. The system is designed to scale to 1,000,000 tracked objects, and the system supports probability annotations and multiple data sources.

This demo uses TLEs for input, and the service propagates these TLEs using SGP4. In addition, the service is designed to support high resolution ephemerides and pluggable interpolators. Note that this service emits "reports" rather than "alerts" to suggest that the former be used in subsequent analysis to generate the latter when warranted.

The core of the service is a custom distributed spatial-temporal streaming index, which runs in main memory across multiple machines. For the current version, a large-scale deployment tracking 100,000 objects with a three-day horizon would use approximately 5TB of RAM.