Rachit Bhatia, LeoLabs; Darren McKnight, LeoLabs; Erin Dale, LeoLabs; Mohin Patel, LeoLabs
Keywords: space domain awareness, statistical risk assessment, conjunction assessment, astrodynamics
Abstract:
Knowledge of the operational environment is critical in any scenario and when the scenario involves a satellite in space then the domain awareness is significant. Space Domain Awareness (SDA) is the technical capability to collect, analyze, and process the data pertaining to the objects in space such that a continuous catalog of their activities and their operational environment can be maintained. A lot of studies, especially in recent years, have focused on the population distribution of the space objects and the associated conjunction risk, however, the studies to understand the distribution of the conjunction events (specifically high-risk events) have been relatively fewer in number.
This study presents the latitude/longitude distribution of the high-risk (probability of collision > 1e-6) conjunction events in the Low Earth Orbit (LEO, region between 300 and 2,000 km altitude) over last 1.5 year time-period and this distribution is analyzed with respect to various parameters, including conjunction type, event altitude, probability of collision, miss distance, conjunction risk (kg), inclination, and right ascension of ascending node of the two objects, respectively.
The comparison of the distribution for the events tracked by LeoLabs and JSpOC is presented and corresponding insights about the spread of their respective sensor network and the impact on the event detectability is shared. The global network of two UHF and eight S-band radars, built and operated by LeoLabs, provide a 24/7 data feed to power this assessment and help identify the evolution of these events and related dynamics. The ability to access this data in near real-time, and provide necessary alerts and services to the customers, significantly enhance operational safety, and enable investigation of specific impacts on different subgroups.
Latitudinal distribution, for all high-risk conjunction alerts, shows characteristic peaks near 50 degrees North and South, along with smaller spikes around equatorial and polar regions. Whereas, for the longitudinal distribution, it is noted that the high-risk events are almost uniformly distributed. While the average distribution for all high-risk conjunction alerts do not change with time, the distribution varies for other parameters, like latitudinal distribution for conjunctions between two fragments is different from that between two operational payloads. This kind of detailed analyses can help understand inherent trends and provide useful insights. This distribution is studied over 1.5 year long time-period and the changes in distribution due to recent launches and / or expansion of the sensor network are also noted.
Distribution of the classical orbital elements (specifically the inclination and right ascension of ascending node at the time of closest approach) of the objects involved in high-risk conjunction events is also presented. Lastly, this distribution is analyzed with respect to various parameters and classification is done for relevant debris clouds, clusters of risky objects, and constellations.
The results presented in this poster are aimed at better understanding the distribution of high-risk events in LEO and identify the underlying dynamics and parameters at work. The goal is to provide necessary intuition to the reader about the evolution of this risk and check the feasibility of using this newly gained intuition to gain insights about future events.
Date of Conference: September 19-22, 2023
Track: Conjunction/RPO