Orbstack

The Orbstack refers to the living heart of the Daban Urnud: sixteen hollow spheres (“orbs”), each a little under a mile across, clustered about a central axis that spins to create pseudogravity. According to accounts from a Laterran informant, most of the ship’s Forty Thousand residents spend their lives inside this habitat rather than venturing to the exterior or service structures.

Structure and Environment

• Each orb is half filled with water. The water’s surface supports houseboats; roofs and decks are used to grow food.
• When the ship is not under acceleration, doors can be opened to join neighboring orbs, allowing free movement between them.
• The cluster’s rotation provides a steady down‑direction; the spheres and links create a connected neighborhood rather than isolated modules.
• The sixteen orbs are arranged in stacked four‑orb layers; each layer is rotated forty‑five degrees relative to the one below, producing a column a little more than two miles high and a little less than two miles across.
• Spin appears to be on the order of a revolution per minute, matching the “second‑hand” pace seen at the Core wall.
• Light captured on the exterior frame is routed inward along optical trunk lines to illuminate rooftop farms within the orbs.

Engineering and Core

• A cylindrical Core, about a hundred feet in diameter, runs the length of the stack. Its wall rotates with the Orbstack.
• Massive bearings at the ends couple the spinning Orbstack to the non‑spinning icosahedral frame. Traffic between these regions passes through large bearing chambers.
• Major spaces are connected—and can be isolated—by ball valves: captive spheres with a bored tunnel that align for passage and rotate shut to form solid barriers. Ball valves are used between bearing chambers and the Core, and between the Core and each orb’s access shaft.
• The Core wall carries a grab grid and a moving conveyor‑ladder that ferries people along its length. Short rests against the wall provide micro‑gravity that eases travel after long periods in weightlessness.

Access, Nexi, and Command adjacency

• Four great Nexi are spaced along the Core where stacks of orbs meet it. Each Nexus opens to four perpendicular shafts that lead “down” to an orb through a ball valve.
• By convention, the lowest‑numbered orb in each four‑orb stack connects at these Nexi: 1, 5, 9, and 13. Offices, meeting rooms, and ring‑corridors—sometimes called the Command torus—wrap this part of the Core and serve the ship’s leadership within the Geometers community.

Communities and Organization

• The Orbstack houses communities from the four origin peoples: Urnud, Tro, Laterre, and Fthos. Officially, each maintains four orbs, though mixing occurs.
• Numbering and assignment: Orbs 1–4 are Urnudan; 5–8 Tro; 9–12 Laterran; 13–16 Fthosian. Within each set, the lowest number (1, 5, 9, 13) is associated with higher‑ranking households; for example, Orb 5 houses high‑ranking Troäns.

Relation to the Ship Frame and Protection

• The Orbstack is suspended within a rubble‑shielded icosahedral frame by a network of giant shock pistons that isolate it from impacts and vibration.
• Systems that interface with the outside universe—sensors, telescopes, scout craft, and weapons—are mounted on the pistons and at the twelve vertices where pistons meet.
• Several vertices are themselves complex vehicles or stations: some are pressurized command spheres; others provide wide tunnels for traffic between the interior and open space; one vertex functions as an optical observatory benefitting from vacuum seeing conditions.
• The rubble shield—essentially walls of gravel hung on the frame—provides protection against sunlight, stray rocks, cosmic rays, and hostile action.

Operations and safety (observed in use)

• During an urgent response centered on the forward bearing and the external weapons complex nicknamed the World Burner, bearing‑chamber traffic and ball‑valve closures illustrated how the Core can be isolated quickly while responders and firefighters move between regions.

Role and Status

• Provides habitation, food production, and services for the ship’s population; suits the long‑duration voyaging purpose of the Daban Urnud.
• Most residents seldom see the exterior of the vessel, living entirely within the Orbstack’s linked orbs.

Notes on Sources and Certainty

Earlier descriptions drew heavily on model‑based reconstructions from a Laterran account. Direct entry and movement through the Core and a Nexus have since confirmed specific features (ball valves between major spaces; a roughly hundred‑foot Core diameter; conveyor‑ladder along the Core; nexus openings to orbs 1/5/9/13; high‑status use of the lowest‑numbered orb in each stack). Where details remain uncorroborated beyond those observations, they are retained with appropriate caution.

Notes on Usage

• The term is often used with an article (e.g., “the Orbstack”).