Scalable Conjunction Processing using Spatiotemporally Indexed Ephemeris Data

ABSTRACT: To reduce the risk of on-orbit collisions, the Joint Space Operations Center (JSpOC) tracks objects in its Space Catalog and forecasts potential conjunctions. Because both the size of the Space Catalog and its ephemeris update frequency are expected to grow significantly in the near term, the methods for conjunction analysis will need to incorporate new filtering techniques to more quickly winnow the list of potential conjunctions. Stellar Science will leverage their extensive software engineering, geometric processing, orbital analysis, space situational awareness, and parallel processing expertise to provide an effective filtering method for conjunction analysis of 100,000 or more space objects whose ephemeris are updated four times a day. We will develop a spatiotemporal index that reduces the computational run time by quickly finding nearby satellites using a relatively fine partitioning of orbital space, and eliminating all other candidates. We will evaluate whether a fixed spherical grid, k-d tree, spatial hash, or other index method provides the best throughput for the volume of data, and implement a prototype using the best approach. Our software methodology will ensure that the tool can be integrated with future tools such as the Continuous Anomalous Orbital Discriminator (CAOS-D) or the JSpOC Mission System (JMS). BENEFIT: Timely and accurate conjunction filtering is a critical need of the Joint Space Operations Center (JSpOC). The collision warnings produced by the JSpOC are of critical importance in protecting U.S. and allied spacecraft against destructive collisions, and in protecting the lives of astronauts during space flight. By reducing the number of objects requiring high-fidelity and computationally-intensive conjunction analysis, Stellar Science will enable the JSpOC to continue to perform its mission in the future as the number of tracked space objects and debris particles grows to exceed 100,000. In addition to benefitting JSpOC, this technology can be used aid the Naval Space Command (NSC), the National Aeronautics and Space Administration (NASA), and commercial satellite owners and operators in protecting their valuable and irreplaceable space assets from space debris. Future commercialization applications also include air traffic control, a domain that also requires predicting and avoiding collisions among multiple fast-moving objects.