Kevin Kuciapinski, CelesTrak; T.S. Kelso, CelesTrak
Keywords: SSA, GP, TLE, launch, operations, maneuvers, conjunction, propagation, proximity, SGP4, data, safety, tracking, position
Abstract:
Traditional Space Situational Awareness (SSA) data alone is inadequate for modern space operations such as multi-satellite launches, close proximity deployments, and mega-constellation operations. Due to changes in the modern space operations environment, launches of more than fifty satellites at a time are now common, satellites are extremely small in comparison to the historical size that traditional SSA data and techniques were developed around, and satellites fly in formation clusters. These changes, in combination with the increase in overall congestion of the Earth Orbital Environment require more precise SSA data and processing techniques, with low latency, to support space operations and Space Flight Safety.
Supplemental General Perturbations (SupGP) Element Sets have proven effective in supporting modern space operations and enhancing Space Flight Safety. SupGP Element Sets are derived directly from owner/operator-supplied data. Until recently, all GP data provided to the public have been derived from radar and optical observations of the US Space Surveillance Network (SSN). This process can cause problems, particularly for deep-space objects (orbital periods greater than 225 minutes) which rely on optical observations. Limited geographic distribution of these optical sites, together with unpredictable weather conditions, can result in long intervals between observations, resulting in delays in cataloging objects, old and inaccurate data, and even difficulty in recovering objects.
While this uncooperative approach to tracking space objects is required for a large portion of the current satellite catalog, many of these objects are operational payloads which are routinely tracked by their owners or operators. Some of this orbital data, such as for the GPS constellation, is publicly available via the Internet. Working with owners, operators, and public data, platforms such as CelesTrak have been able to produce and share SupGP data with the public for 65% of the operational satellites on orbit. SupGP data has provided significant and measurable increases in accuracy, timeliness, and Space Flight Safety.
This paper discusses and provides recent and relevant examples and comparisons between SupGP data and traditional SSA data to illustrate the need for SupGP data incorporation across the Space Operations Community. One such example is the GALAXY 25 (G-25) maneuver from GEO orbit to a Circularized GEO Graveyard Orbit from Dec 5, 2022, to Dec 12, 2022. SupGP processes and data provided precision position information all throughout the maneuver, to a level of detail where thruster fires were observed. Continuous situational awareness was provided to all other space operators who may have needed to make decisions for their own maneuvers or even conjunction avoidance.
By comparison, if a space operator had relied on the traditional SSA data alone it was not possible to know that G-25 was maneuvering. Using only the traditional SSA data, the first indication of the Dec 5, 2022 G-25 maneuver was not until Dec 19, 2022, when the traditional SSA data shows G-25 makes an instantaneous orbital jump of over 38,000km (55 degrees) directly to the GEO Graveyard Orbit. The first indication of the G-25 maneuver in the traditional SSA data was not until 14 days after the maneuver began and 7 days after the maneuver was complete and G-25 was stabilized in the GEO Graveyard Orbit.
The problems and risks of relying on such inaccurate and delayed data for space operations, maneuver decisions, and conjunction avoidance are obvious. The risks and potential for a catastrophic event are significantly greater when increased congestion and modern space operations are considered, such as: multi-satellite launches, close proximity deployments, formation flight clusters, and mega-constellation operations.
The SupGP data approach offers several advantages in accuracy, timeliness, redundancy, and ease of use over traditional SSA data. All SupGP advantages offer improvements in Space Flight Safety and increased precision required for modern space operations.
SupGP data and processes have been rigorously tested, verified, and validated. Details of SupGP data, SGP4 fitting, convergence criteria, and RMS calculation results is discussed. Additional recent and relevant example comparisons between SupGP data and Traditional SSA data are provided with graphic illustrations to reinforce the benefits and the space community’s need for adoption of SupGP data at present and in the future. There is a compelling necessity to share SupGP data across the space community in the interest of Space Flight Safety for all and to ensure the Earth Orbital Environment is preserved for future generations.
Date of Conference: September 19-22, 2023
Track: Astrodynamics