H1: Phase-Guided Graphene Thermal Shield — Thermal Routing, Recession, Latency and Mass Constraints

H1 investigates whether phase-guided redistribution of lateral heat transport can improve thermal-shield response and whether this improvement translates into lower admissible normalized areal mass. The numerical sequence, H1.1–H1.12 with the H1.12R closure, progresses from conservative thermal-sheet baselines and passive anisotropy to multilayer transport, phenomenological ablation and surface recession, prescribed defects, moving heat loads, effective control latency, and constrained mass reduction.Controlled comparisons separate transport topology, retained-state memory, sink steering, and thermal-protection outcomes. The early experiments support directional redistribution and useful persistence of the control state, but do not establish a unique phase mechanism: static phase-guided routing is effectively coincident with direct-demand routing, while the tested memory response reproduces the advantage of a classical sample-and-hold control. A simple kinematic phase-advance law does not extend the tested operational latency boundary.The final numerical audit distinguishes precision sensitivity from performance and extends observation beyond the original evaluation window. At equal normalized mass, the delayed phase architecture reduces the captured late back-face temperature peak relative to passive few-layer graphene (FLG) by approximately 1.389% in the nominal case and 1.044% under the prescribed 25% dropout. However, this thermal benefit does not produce an additional mass-saving advantage. In the extended comparison, the locally admissible phase-guided configuration requires slightly more normalized mass than the passive FLG configuration. Peak surface recession, rather than the back-face thermal limits, determines the new mass boundary.The central result is a separation between improved thermal response and achievable mass reduction under simultaneous constraints. The findings apply to the tested family of normalized, reduced-order models. They do not establish measured graphene properties, physical mass savings, a manufactured thermal shield, or flight performance.