Presenting BACARDI's Sub-Catalogue of drifting Objects close to the Geostationary Ring

Abstract

Since the beginning of its operational phase in 2017, observations with the Small Aperture Robotic Telescope Network (SMARTnet) have primarily focused on observations of Resident Space Objects in the geostationary ring, including geosynchronous objects and Resident Space Objects in so-called graveyard orbits. Those latter Resident Space Objects are uncontrolled and are potential candidates for fragmentation events and pose a threat for the geostationary ring as a whole. After two network extensions with telescope stations in Australia (2019) and Chile (2024), almost the entire geostationary ring is now within the observational reach of the SMARTnet stations. Drifters may be observable throughout their drifting period, i. e., the time after which a Resident Space Object is again above the same longitude. We therefore launched a study to investigate the number of drifters in the Backbone Catalouge of Relational Debris Information (BACARDI) database. In terms of orbital regions as defined by the European Space Agency, we focused on Resident Space Objects that spend some time in the geostationary ring, deliberately excluding Resident Space Objects of the Geostationary Orbit themselves. One particular focus was put on orbits with a perigee below the geostationary ring, an apogee above it, and an inclination lower than 15°. These Resident Space Objects are crossing the geostationary ring regularly and pose a threat to active satellites. Tracklets were selected that represent Resident Space Objects in these regions. The filter process happened against the publicly available Two Line Element set catalogue. Additionally, we present a number of tracklets from the BACARDI database that are associated with Resident Space Objects in those regions but do not have a counterpart in the Two Line Elements catalogue. These Resident Space Objects shall be observed from every available telescope station in order to determine orbit updates. It is imperative not to lose track of them again, for they still pose a threat to the space environment.