Navraj Singh, Numerica Corporation; Holly Borowski, Numerica Corporation; Jacob Brannum, Numerica Coorporation; Alex Ferris, Numerica Corporation; Joshua Horwood, Numerica Corporation; Jeff Aristoff, Numerica Corporation
Keywords: Space Situational Awareness, Space Domain Awareness, Indications and Warning, Small Autonomous Telescope Systems, Sensor Tasking and Scheduling
Abstract:
With the increase in new foreign launches and the number of agile or potentially separable satellites being placed in and near geostationary Earth orbit (GEO), it is critical that satellite operators not only maintain custody of these satellites, but also quickly identify and interpret changes in behavior. Thus, one key component of space domain awareness (SDA) is automated indications and warning (I&W). Real-time alerts indicating events such as maneuvers, changes in stabilization or attitude, on-orbit breakups, collisions, or potential conjunctions and proximity operations are critical for maintaining situational awareness, verifying nominal operations, and ensuring the safety of orbiting spacecraft.
To help address this need, Numerica Corporation has combined advanced algorithms, high performance software, and a globally-distributed network of small telescopes to demonstrate a responsive deep-space tracking system. Observations from the Numerica Telescope Network (NTN) are processed via a Multiple Frame Assignment Space Tracker (MFAST) to create and maintain an independent catalog of objects in multiple deep-space orbital regimes. Further, the NTN produces real-time I&W alerts. These I&Ws currently include maneuver, conjunction, photometric, and no-show alerts. In addition, a multi-source event correlation layer automatically determines certain types of relationships (e.g., co-occurrences) between events detected across multi-source data, which can aid in mitigating false alarms generated by a single data source. The alerts are disseminated in real-time to end users via the NTN application programming interface (API) and user interface (UI). Furthermore, Numerica has pushed real-time maneuver and conjunction alerts to the Unified Data Library (UDL) under the Commercially Augmented Mission Operations (CAMO) program.
The NTN consists of (i) small aperture, wide field-of-view sensors arrays, known as Argus sensors, that provide persistent coverage of a large swath of the night sky and (ii) medium aperture, fully-robotic and taskable telescopes that provide increased detectability and resolution with a smaller field of view. In particular, the Argus sensors’ persistent coverage of GEO enables change detection to generate meaningful and consistent I&W alerts, which can in turn provide tipping and cueing for larger telescopes (in the NTN or in other telescope networks).
NTN I&W production is enabled by several software components, including MFAST, Athena, and the Kollision Risk Assessment Tool in Orbital Element Spaces (KRATOS) components of the NTN pipeline. MFAST produces maneuver alerts when a change is detected in an object’s orbital state that is inconsistent with natural orbital dynamics. These alerts contain an estimated time and delta-V associated with the maneuver. No-show alerts are produced when an object’s orbital state should have been updated using a sensor observation, but was not. A no-show alert may indicate a maneuver or brightness/orientation change, and can be used to cue sensors to search for that object. Athena produces photometric change alerts, which can indicate a change in an object’s stabilization state, attitude,or orbital state. Finally, KRATOS computes miss distances and produces probabilities of collision for potential conjunction events.
In this paper we demonstrate these I&W capabilities using real-world scenarios, in which the NTN I&W Suite generated the aforementioned alerts in real-time. Examples of scenarios discussed include maneuvers into geostationary transfer orbits, docking events, and changes in satellite stabilization state. We will also discuss tasking sensors based on information gathered from these alerts, enhancing our overall space awareness capabilities.
Date of Conference: September 15-18, 2020
Track: Optical Systems Instrumentation