Safe and Optimal N-Spacecraft Swarm Reconfiguration in Non-Keplerian Cislunar Orbits

The paper defines the first‑order QPRIT/QPRO condition in LTC (h = dot α = dot β = dot h = 0, equivalently h = dot ε = dot θ = dot h = 0), and proposes constraints (21a)–(21b) to enforce proximity to that invariant surface while keeping ε above the terminal radius ε_f, asserting this suffices for passive safety. The candidate solution follows the same logic, adds routine bounds on dot ε and dot θ from dot α, dot β using ε = sqrt(α^2+β^2), and reaches the same safety conclusion. Minor caveats (e.g., dependence on KOZ geometry and the non-orthonormal LTC frame) are shared and do not overturn the core argument.