Instability of Self-Driving Satellite Mega-Constellation: From Theory to Practical Impacts on Network Lifetime and Capacity

TL;DR

This paper reveals that current collision avoidance maneuvers in LEO satellite mega-constellations can cause instability, threatening network safety and capacity, and proposes a bilateral control method to enhance stability and extend network lifetime.

Contribution

It identifies the instability problem in existing maneuver paradigms for mega-constellations and introduces a bilateral maneuver control to improve stability and network longevity.

Findings

8× extension of network lifetime in Starlink simulations

Current maneuver paradigm causes cascading collisions and instability

Proposed bilateral control stabilizes the constellation without capacity loss

Abstract

Low Earth Orbit (LEO) satellite mega-constellations aim to enable high-speed Internet for numerous users anywhere on Earth. To safeguard their network infrastructure in congested outer space, they perform automatic orbital maneuvers to avoid collisions with external debris and satellites. However, our control-theoretic analysis and empirical validation using Starlink's space situational awareness datasets discover that, these safety-oriented maneuvers themselves can threaten safety and networking via cascaded collision avoidance inside the mega-constellation. This domino effect forces a dilemma between long-term LEO network lifetime and short-term LEO network capacity. Its root cause is that, the decades-old local pairwise maneuver paradigm for standalone satellites is inherently unstable if scaled out to recent mega-constellation networks. We thus propose an alternative bilateral maneuver control that stabilizes self-driving mega-constellations for concurrent network lifetime and capacity boosts. Our operational trace-driven emulation shows a 8$\times$ network lifetime extension in Starlink without limiting its network capacity.