Concordia
The terminal nave seen down its 440 m length: ribbed walls, handline conveyors with riders, catch-net rings and gate signage.

The spaceport

Everyone who arrives from Earth or the Moon comes through the spaceport at the forward end. Passengers float through a zero-g terminal; freighters berth on long piers outside; propellant waits in a tank farm well clear of the station.

See on the map

What you see

The terminal is one long tube, 440 m by 84 m across, in the same Art Deco language as the city: stone ribs every 20 m, warm light coves and bronze-framed windows. Only the space people use is pressurized, so it holds about 2 million cubic metres of air, not 55 million. One flank looks onto the axial bay, so berths and craft are always in view; the other looks out at the three lounge wheels turning in the open. It is stationary and in zero g. "Up" is where the lamps are, and a stone deck below carries the shops.

Arrival follows one path. The express ends at the spine terminus. A walkway 56 m wide carries you to a monumental arch under a lit panel reading WELCOME TO CONCORDIA. Then three rings across the tube: health screening, customs with eight lanes, and security with eight arches. Then the concourse. Nobody is ever more than 15 m from something to hold: eight conveyor lines of grab handles carry travellers along the tube at walking pace (amber lines to the gates, blue to the lounges), a cable runs down the axis, and a catch net spans the tube every 60 m.

Rotating comfort lounges turn on their stationary hubs beyond the windows of the terminal nave.
Rotating comfort lounges on their stationary hubs, seen through the windows of the nave. Open this view

Five gates, A01 to A05, open off the bay flank. Each has an arch in the shell, a gate pod, a telescoping boarding bridge 60 m long and a berth in the axial bay for a docked craft. At the east end a dock hall holds the passenger trunk to pier P1 and four small docks, S1 to S4, for couriers. Crews reach cargo and tug bays by their own route, so freight never shares a bridge with passengers.

Comfort lounges

Three wheels beyond the far flank give travellers a rest from weightlessness, at 0.13 g, 0.20 g and 0.28 g. You float to the stationary hub, enter a transfer chamber spun to match, and ride a spoke to the rim to find restaurants, sleeping rooms and a quiet deck.

Piers and the propellant farm

Large ships do not dock inside. They berth at three piers on the outer face of the port, each a deep truss running 900 m. Articulated arms clamp a ship alongside, and freighters are 260 m long. Pier P1 is the passenger pier, with a pressurized trunk that runs straight on from the axis of the terminal.

A freighter berthed at a long truss pier on the outer face of the port, with tugs and the axial aperture nearby.
A freighter alongside a truss pier on the outer face of the port, with tugs and the axial aperture. Open this view
Meridian 04 held in her capture rings inside the shipyard, with tension lines spread to the yard frame and a tank mover alongside.
Nearby, the zero-g shipyard: Meridian 04 held in her capture rings, with tension lines spread to the yard frame. Open this view

Beyond the piers, outside the station body, is the propellant farm: two liquid hydrogen spheres, two liquid oxygen spheres and two storable-propellant cylinders under sunshades, with cryocoolers that re-liquefy the boil-off. It sits clear of the approach lane and well away from the city's pressure vessels, so a tank failure cannot reach a home.

Foil spheres and storable tanks of the propellant farm sit under sunshades with radiators and transfer lines, outside the station body.
Foil spheres and storable tanks of the propellant farm under sunshades, with radiators and transfer lines. Open this view

How it works in brief

Passengers leaving for Earth do not use a gate. They take the express to the launch berth and ride a launcher along a track outside the hull. That story is in Getting there. The express that brings you here is described in The axis and the spine.

The electromagnetic launch track and its gantries running along the outside of the station hull.
The launcher track outside the hull: a 10 km bed and its gantries, where a carrier takes passengers to 540 m/s in 37 seconds. Open this view

Key numbers

440 mterminal nave
5passenger gates
3rotating lounges, 0.13 to 0.28 g
3piers, each 900 m long
260 mfreighter length
Go deeper: Lounges and docking

All three lounges turn at 2.0 rpm, comfortable for a short stay, and differ only in radius.

Lounge Radius Gravity Rim speed
L1 62 m 0.28 g 13.0 m/s
L2 45 m 0.20 g 9.4 m/s
L3 30 m 0.13 g 6.3 m/s

Lounges 1 and 3 turn one way and lounge 2 the other, so most of their angular momentum cancels. A gate berth is an octagonal cradle 85 m deep with four capture arms and a docking collar 5.5 m in radius.

The propellant farm begins about 11,420 m along the station, at least 355 m outside the 1,500 m approach cylinder and about 1.4 km beyond the nearest defence battery. The farm holds spheres of 16 m radius (hydrogen) and 12 m radius (oxygen), and cylinders of 6 m radius.

Visit

Open in the simulation: Passenger Spaceport Terminal Open in the simulation: Spaceport Arrival Face Open in the simulation: Spaceport Concourse A Open in the simulation: Spaceport Gate A03 Open in the simulation: Spaceport Rotating Lounges Open in the simulation: Spaceport External Pier

Nearby

The zero-g shipyard

The shipyard is a stationary vacuum yard about 3.5 km long, with no floor and no up.

The axis and the spine

At the centre of every rotor you weigh almost nothing, and a stationary tube 120 m wide runs the whole length of the station.

The exterior

From outside, Concordia is a grey cylinder 21 km long and 6.2 km wide.

  • The zero-g shipyard The shipyard is a stationary vacuum yard about 3.5 km long, with no floor and no up.
  • The axis and the spine At the centre of every rotor you weigh almost nothing, and a stationary tube 120 m wide runs the whole length of the station.
  • The exterior From outside, Concordia is a grey cylinder 21 km long and 6.2 km wide.
  • Getting there from L5 Concordia floats in the Earth-Moon L5 region, 384,400 km from Earth.