Concordia
An ascender cabin rises through the open floor of the artificial sky, with the curved city and a lit ceiling ahead.

Places in Concordia

Concordia is a few dozen kilometres of streets, farms, factories and docks. Start on the ground at a full 1 g, climb toward the axis where weight vanishes, then follow the station out to its ports and its skin.

A tour from the ground up

Gravity is the map. The farther you are from the axis, the more you weigh, so the tour runs from the heaviest places to the lightest and then out into space.

A quiet residential street of mid-rise blocks lined with trees, with the curved city rising ahead under a bright artificial sky.
The heavy end of the tour: a street at the ground, where you weigh 1 g. Open this view
Inside the 120 m spine tube, ring lamps every 25 m frame the express guideway, crew galleries and four utility trunks.
The light end: the stationary spine on the axis, where nothing weighs anything. Open this view
  1. Arbor Quarter is a groundside neighbourhood at 1 g: streets, a lake park and the metro.
  2. The megaframe city is the second city on plates and bridges above the streets, and the inhabited cliffs of the end walls.
  3. Ascenders and the sky is the ten-minute lift through the artificial sky.
  4. Upper city farms grow the food at 0.6 g.
  5. The axis and the spine is where you change from the turning city to the still tube that runs the length of the station.
  6. Ehricke, the industrial rotor turns against the city and stores lunar and asteroid material.
  7. The zero-g shipyard builds 700 m ships in a vacuum yard.
  8. The spaceport is the passenger terminal, the piers and the propellant farm.
  9. Aft works lands the station's power and holds the reactors and thrusters.
  10. The exterior is the hull, the radiators, the defences and the satellites.
The whole station in space, a grey cylinder with a caged ring section, radiator banks and attached utilities.
The whole station in space, a grey cylinder with a caged ring section, radiator banks and attached utilities. Open this view

Every place opens in the simulation, and each page links to the science behind it. For the numbers behind the whole station, see Concordia at a glance. To follow one family through a day, start the Journey.

Open in the simulation: Start on the ground Open in the simulation: See the whole station

All places

Every place is below in tour order, with its lead and a way into the simulation.

In this section

Arbor Quarter

Arbor Quarter is a neighbourhood on the floor of Tsiolkovsky (Rotor 1), where the ground weighs what it does on Earth.

The megaframe city

Above the streets, a lattice of piers and ring beams holds a second city on plates, bridges and terraces. The lattice is the megaframe.

Ascenders and the sky

The ascender is a lift 2.4 km tall. It carries 150 people from the street through the artificial sky to the axis in about ten minutes, and on the way your weight drops to almost...

Upper city farms

Food is grown high in each rotor, where gravity is 0.6 g and the air is the same air the city breathes.

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 industrial rotor

Ehricke, the industrial rotor, is the factory floor. It is a skeleton of rings and girders 3.5 km long, turning opposite the city rotors, with refineries, tank farms, container...

The zero-g shipyard

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

The spaceport

Everyone who arrives from Earth or the Moon comes through the spaceport at the forward end.

Aft works

The back of the station is where the electricity comes in. Eight tethers run 7 km aft to the solar farm, four masts land the power, two reactors can restart everything after a...

The exterior

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

  • The station at a glance Concordia sits in the Earth-Moon L5 region, 384,400 km from Earth.
  • A day aboard A family of five lives in the Arbor Quarter of Tsiolkovsky (Rotor 1). Today they leave Concordia for Earth.
  • How Concordia works Gravity from spin, shielding from rock, air from plants and power from sunlight. These pages explain each system in plain language, then show the numbers.