Roohi Dalal, Outer Space Institute; Aaron Boley, Outer Space Institute and University of British Columbia; Michael Byers, Outer Space Institute and University of British Columbia
Keywords: Nuclear Command Control and Communications, Collision Risks, Attribution
Abstract:
Space-based assets, such as early warning and communications satellites, form an important part of the United States National Nuclear Command, Control, and Communications (NC3) system. However, in recent years, states including Russia and China have been developing counterspace military capabilities to target these satellites. Such anti-satellite weapons aim to deny the U.S. the ability to conduct NC3 in addition to space-based intelligence, surveillance, and reconnaissance, as well as positioning, navigation and timing. In addition to threats of intentional interference, space-based assets also face hazards from their orbital environment, particularly the growing amount of space debris. This novel web of threats raises several questions, including whether satellite failures due to debris impacts could be mistaken for intentional counterspace operations. This possibility is particularly worrisome, as the U.S. has historically maintained the option of a nuclear response to non-nuclear attacks on its NC3 architecture. I evaluate whether the growing population of space debris could destabilize nuclear strategic stability by first characterizing the frequency and severity of debris and meteoroid collisions with NC3 satellites. I then assess existing technological capabilities to rule in or rule out debris impacts as a cause of satellite failure, as opposed to intentional interference with satellites, e.g. in the form of cyberattacks.
I characterize the threat from debris to NC3 systems in geostationary orbit (GEO) in terms of both the expected collision frequency and the potential damage caused by such collisions, focusing on the impact of debris pieces smaller than the limits of U.S. tracking systems (~1 meter in GEO). In particular, I highlight the dangerous, and often under-appreciated, population of debris in GEO-crossing orbits. While GEO satellites might not face a significant threat from debris within GEO, there is serious potential for damaging collisions from objects in highly eccentric orbits that cross through GEO. The expected frequency of collisions between GEO satellites and a debris object larger than 1 cm is at least once per every four years. I use the NASA Standard Breakup Model to show that collisions with small, untrackable debris particles could severely damage a satellite without fully fragmenting it, i.e. cause the satellite to fail without clear evidence of a breakup that one would be able to detect with existing tracking systems.
Upon concluding that cratering events due to debris collisions are both likely and able to cause irreparable and potentially unobservable damage to satellites, I then discuss possible observational signatures of debilitating debris impacts to assess whether such impacts could be distinguished from intentional attempts to incapacitate satellites, such as cyberattacks. I show that the expected satellite displacement after a debris collision is much smaller than the uncertainties associated with the U.S. Space Surveillance Network orbit predictions. Instead, I recommend observational methods to detect changes in the satellite attitude due to collisions, including Satellite Laser Ranging and Inverse Synthetic Aperture Radar imaging.
Noting that the U.S. Space Force is planning to phase out the use of GEO satellites for early warning, and instead move to a proliferated low earth orbit (LEO) environment with the Proliferated Warfighter Space Architecture (PWSA), I similarly evaluate the threat from debris in LEO and our ability to attribute satellite failures in these lower altitude orbits. While the debris population in LEO is much higher than that in GEO, and satellites in LEO are more vulnerable to deliberate attacks, our debris tracking capabilities for this closer orbit are much better, with the ability to track and avoid debris down to much smaller sizes. Additionally, observational follow-up after satellite failures would be quicker and easier due to the proximity to ground-based sensors. I suggest that it is unlikely that a debris impact could be mistaken for a counterspace attack against a satellite in LEO, i.e. LEO debris is not as destabilizing as the debris to which GEO satellites are vulnerable.
Date of Conference: September 17-20, 2024
Track: Space Domain Awareness