Five ports. One heart. Continuous flow.

The Oakheart is deliberately kept light. Its primary functions are structural docking, propellant routing, and control. Short transfer lines minimize thermal losses. The manifold allows any port to connect to any other port or to the small internal buffer. Attitude control, power, and communications are sized for a permanent but modest orbital presence.

Radial symmetry provides balanced loads and clear approach corridors. One port is designated as the reserve berth. The other four are active berths. All five use the same standardized docking and fluid-transfer interface, ensuring any Starship can occupy any position.

Starships remain the tanks. The hub never becomes a massive cryogenic warehouse. This choice avoids the hardest long-duration storage problems — boil-off management at scale, complex insulation, and large structural mass — while still delivering the benefits of staged propellant and parallel transfer.

Five ports keep the system compact enough for manageable moments of inertia and thermal gradients. The reserve Starship provides both propellant and additional thermal mass. The design accepts the complexity of multi-vehicle proximity operations in exchange for dramatically higher transfer throughput and operational tempo.