This analysis maps the rapidly emerging orbital compute supply chain, showing how thermodynamics is now the dominant constraint driving new suppliers, capital flows, and talent demand. While consolidation and vertical integration (in particular SpaceX) will squeeze many early-stage component players, major breakthroughs in solar arrays and radiator technologies remain essential to reach viable 100 kW/ton power densities, creating a narrow set of high-risk, high-upside frontier investment opportunities.