Why here
The regime that behaves like Earth.
Earth orbit is the one place off the surface where a failed system is an inconvenience rather than a death. Resupply is days, not years. A crew can come home in hours. The radiation dose below the inner belt is a fraction of what it is anywhere past the magnetosphere. Every constraint that defines the rest of the solar system is here reduced to a manageable number.
Which is exactly why it is first, and why it is misleading. The station era, the orbital-manufacturing pitch, the compute-in-orbit thesis all close here on economics that do not survive being moved outward. The value of this regime is that it is forgiving. The danger is reading that forgiveness as general.
Envelope
What bounds it.
The constraint fingerprint — the parameters that are fixed, time-invariant, and must be designed around rather than defended against. Each is paired with the consequence it forces.
| Parameter | Value | Consequence |
|---|---|---|
| Transport Δv | 9.4 km/s from surface | Sets launch cost; the one number the whole economy hangs on |
| Power | Solar, near-continuous | No storage penalty in sunlit orbits |
| Light time | Sub-second | Real-time control from the ground; no autonomy required |
| Local resource | None | Everything is imported; there is no ISRU case in LEO |
| Thermal | Managed by attitude | Radiators sized against sunlight, not against distance |
Hazards
What damages it.
Hazards are not constraints. A constraint bounds what is possible; a hazard accumulates, has a return period, and is defended against. Kept in a separate table on purpose — the distinction is the point.
| Hazard | Character | Defence |
|---|---|---|
| Orbital debris | Cumulative, worsening | Shielding and collision-avoidance; the one hazard that grows with use |
| Trapped radiation | Bounded below the belt | Altitude selection; the inner belt sets a soft ceiling on LEO |
| Atomic oxygen | Continuous in LEO | Material selection; erodes polymers and coatings |
| Congestion & slots | Regulatory, rising | Coordination, not engineering; the crowded regime |
Four readings
The same place, four questions.
Each of the four topologies asks a different question of the same body. A destination that looks marginal under one can look essential under another, which is the reason the maps are kept separate.
Cheapest regime to power. Continuous sunlight, no storage penalty, no distance loss.
The demand centre, not the supply. Everything flows in; finished high-value goods flow out.
Almost none. Sub-second light time, days to resupply, hours to return.
Debris is the exception — the one hazard that accumulates with the regime’s own success.
Matter inventory
What is actually here.
Earth orbit produces nothing and imports everything. That is not a deficiency of the regime, it is its definition: the near shore is a market for launched mass, and the entire industrial argument is about driving the cost of that mass down until orbital production of specific high-value goods — fibre, crystals, pharmaceuticals — beats making them on the ground and lifting them. The matter question here is a cost question, not a geology question.
Corridors
Where it connects.
The edges into and out of this node, with the Δv and status each carries. Full detail on the corridors page.
| Corridor | Δv | Carries | Status |
|---|---|---|---|
| LEO → GEO | 3.9 km/s | The reference commercial corridor | Flown |
| LEO → EML-1 | 3.8 km/s | The gateway to everywhere else | Flown |
| Surface → LEO | 9.4 km/s | The launch leg every other corridor sits on top of | Flown |
Contested
Deliberately Not Claimed
The load-bearing uncertainties, stated as uncertainties. Each is tagged with the confidence it actually earns rather than the confidence the argument would prefer.
Orbital manufacturing at scale is unproven. Microgravity production of fibre and crystals works at demonstration scale. Whether it closes as an industry depends on launch cost continuing to fall, and on downmass capacity that does not yet exist in volume.
Orbital compute economics are a launch-cost bet. The pitch — free cooling, no permitting, continuous power — is real, but it is denominated entirely in dollars per kilogram to orbit. If that number stops falling, the case does not close.
Record
Provenance.
- Presence
- Crewed, continuous since 2000
- Anchor regimes
- LEO, GEO, and the belts between
- Sources
- The Orbital Economy; The Free-Fall Regimes
- Reviewed
- Q3 2026