LAGRANGE COMMON / EARTH–MOON L5 / 2280

Beyond planets,
the city carries its own ground.

An artificial-gravity city of 160,000 turns where neither the Moon nor Mars fills the ground. Gravity, daylight, landscape and ecology are designed, and migration can begin from any world.

ENTER THE CITY / 2280 ↓

RESIDENTS / 160,000HABITAT RADIUS / 2.4 KMROTATION / 0.61 RPMCIVIC GRAVITY / 0.9 G

A CITY THAT CARRIES ITS OWN GROUND

BEYOND PLANETARY GROUND

The Moon built a city. Mars built self-rule.
Orbit builds the ground itself.

Lagrange Common is not an enlarged spacecraft. Its rotating inhabited surface, non-rotating logistics axis, shielding, water, soil and transit are one continuously renewed artificial territory.

Gravity is public infrastructure here. Bodies raised on Earth, Moon and Mars choose different districts and different periods of adaptation.

01 / CITY FORM

The inhabited surface rotates.
The port does not.

Separate the outer city from the central docks so maintenance and movement continue without stopping rotation.

The cylinder's outer surface turns slowly, producing 0.9G for homes, schools, farms and parks. The central axis remains near weightless for ships, fuel and construction loads.

Several transfer hubs join rotating and stationary structures. A city is defined less by its diameter than by its ability to replace parts while people keep living inside.

RESIDENTS: 160,000
HABITAT RADIUS: 2.4 KM
ROTATION: 0.61 RPM
AXIAL PORT: 6 DOCKS

02 / GRAVITY

Gravity is not one setting.
Residents choose where to adapt.

Moving from the 0.9G rim toward the near-weightless axis becomes a choice of gravity.

People from Earth begin near the rim. Arrivals from the Moon or Mars spend months in intermediate-gravity districts. Clinics and training spaces occupy several radii so recovery can progress within one city.

Low gravity is not isolated as entertainment. Manufacturing, logistics, sport, care and childhood all have working neighborhoods designed for their own gravity band.

CIVIC SURFACE: 0.9 G
TRANSITION: 0.3–0.7 G
CENTRAL AXIS: MICROGRAVITY
ADAPTATION: 120 DAYS

03 / LANDSCAPE

Sky and terrain are constructed.
They are protected as public goods.

Light, soil, water, airflow and view are shared infrastructure for health and civic life.

Daylight mirrors create a 24-hour rhythm. Seasons change gently with agriculture and culture. Atmospheric scattering and optical surfaces make a blue sky, while the opposite city curves into the distance overhead.

Park soil combines lunar and asteroid minerals with organics cultivated over decades. Water, trees, insects and microbes are maintained as a repairable ecology, not scenery.

LIGHT CYCLE: 24 HOURS
TOPSOIL: 1.8 M AVERAGE
OPEN WATER: 22 HA
ECOLOGY: 12 WATERSHEDS

04 / CITY METABOLISM

Not a sealed loop.
A cycle open to the Solar System.

The city recovers material internally while receiving matter and genetic diversity from several worlds.

Water, air and nutrients circulate by district so contamination cannot spread across the whole habitat. Components carry material histories and return to another district after disassembly.

Total self-sufficiency is not the goal. Shielding comes from the Moon, metals from asteroids, biodiversity from Earth and long-duration operating knowledge from Mars.

WATER: DISTRICT LOOPS
MATERIAL: MOON + ASTEROIDS
BIODIVERSITY: EARTH UPDATES
RESERVE: 5 YEARS DISTRIBUTED

05 / MIGRATION

Destinations are no longer only planets.
People choose gravity and society.

Arrivals from Earth, Moon and Mars select a habitat for their body, work, family and culture.

Migration to Lagrange Common is not necessarily one-way. Lunar cities, Earth orbit and Mars routes connect regularly, and some residents move among worlds for school, work, care or treatment.

Citizenship follows residence and participation rather than birthplace alone. Portable education, health and professional records make movement possible across different gravity environments.

ANNUAL ARRIVALS: 18,000
ORIGINS: EARTH · MOON · MARS
CITIZENSHIP: RESIDENCE + PARTICIPATION
PORTABLE RECORD: EDUCATION · HEALTH · SKILLS

06 / CIVIC CHARTER

The ground is not simply owned.
The conditions of rotation are held in common.

Structure, gravity, air, light and ecology are civic foundations that cannot be governed by ordinary property alone.

Hull maintenance, rotation speed, population limits and farmland conversion affect every district. The structural authority, citizen assembly and watershed unions publish their records, and long decisions require generational impact review.

Lagrange Common is not the final form. It is the first mother city to send material, institutions, skills and hard-earned failures into the next cylinder. Migration into space is no longer a special mission from here.

FOUNDING LAW: HABITAT COMMONS CHARTER
POPULATION LIMIT: STRUCTURE + ECOLOGY
LONG DECISIONS: GENERATION REVIEW
NEXT HABITAT: LC–02 / 2294

SELECTABLE ERAS