  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.
