1. The long now

Vernor Vinge’s A Deepness in the Sky is about civilizations that plan across centuries, preserving capability through cycles of collapse and renewal. The Qeng Ho traders do not commit to one technology; they keep options alive because the right orbit, the right market, or the right customer may not exist for a hundred years. The lesson is not patience as a virtue; it is optionality as an engineering requirement.

Entries 365 through 367 looked at HEO, GEO/MEO, and the orbit trade for the desktop. This entry closes the arc.

2. What was learned

The alternatives are not wrong; they are premature.

  • HEO offers long dwell over one hemisphere at the cost of radiation, thermal swings, and launch complexity. It is a mission-specific choice, not a platform default.
  • GEO offers continuous coverage and stable geometry at the cost of launch energy, latency, radiation, and slot coordination. It is a customer-specific choice.
  • MEO sits between LEO and GEO without a clear first-generation advantage for the desktop’s intended workloads.
  • LEO wins the first-generation trade because it is cheap to reach, well understood, and forgiving. It is the orbit in which the desktop can afford to fail and learn.

3. The decided posture

The Resident will:

  • Keep LEO as the first-generation orbit.
  • Treat HEO as a future variant triggered by high-latitude persistent-coverage requirements.
  • Treat GEO as a future variant triggered by continuous-equatorial-coverage requirements or co-location with GEO customers.
  • Keep MEO as a low-priority option unless a navigation or timing mission appears.
  • Record orbit as an independent design variable that can change without redesigning the whole architecture, provided the radiation and thermal budgets are revisited.

4. What this changes

  • The desktop is not locked into LEO forever; it is optimized for LEO first.
  • Higher orbits are shelved with clear activation conditions.
  • The orbit trade is added to the reference shelf, so future programme phases do not have to re-derive it.
  • The orbit alternatives arc is closed.