suaveplan/openspec/archive/2026-05-05-enterprise-universe-family/specs/geo-planet/spec.md

ADDED Requirements

Requirement: PlanetConfig shape

The system SHALL export a PlanetConfig type containing name, mass, radius, polar radius, surface gravity, rotation period, axial tilt, optional atmosphere, satellites, optional orbital elements, and optional texture manifest.

Scenario: Validate PlanetConfig schema

• WHEN a PlanetConfig with all required fields is constructed via Zod parse
• THEN validation succeeds
• AND when mass is omitted, validation throws ValidationError

Requirement: AtmosphereConfig shape

The system SHALL export an AtmosphereConfig type with surface pressure, scale height, Rayleigh coefficient, Mie coefficient, and extinction per air mass.

Scenario: Validate atmosphere

• WHEN an AtmosphereConfig with valid positive values is parsed
• THEN validation succeeds
• AND atmosphericDensity(0) on a PlanetSurface using this config returns surface pressure-derived density

Requirement: SatelliteConfig shape

The system SHALL export a SatelliteConfig type with name, mass, radius, orbital radius, orbital period, inclination, eccentricity, and albedo.

Scenario: Satellite definition

• WHEN a SatelliteConfig for a moon is parsed with mass > 0 and orbitalRadius > 0
• THEN validation succeeds

Requirement: PlanetSurface geometry delegation

The system SHALL implement PlanetSurface whose distance, bearing, destination, and pointInPolygon methods delegate to @suaveplan/geo functions using the planet's ellipsoid.

Scenario: PlanetSurface uses correct ellipsoid

• WHEN a PlanetSurface is constructed with a planet having radius = 3396200 and polarRadius = 3376200 (Mars-like)
• THEN distance between two surface points matches the great-circle distance on that ellipsoid, not WGS84

Requirement: Atmospheric density

The system SHALL compute atmospheric density at a given altitude from AtmosphereConfig using the scale-height exponential model.

Scenario: Density halves at scale height

• WHEN atmosphericDensity(scaleHeight) is called on a planet with scaleHeight = 8500
• THEN the result equals half the surface density

Requirement: Air mass

The system SHALL compute air mass for a given altitude angle using the Kasten–Young formula.

Scenario: Zenith air mass

• WHEN airMass(90) is called
• THEN the result is approximately 1.0
• AND airMass(0) returns a value significantly greater than 1.0

Requirement: No bundled planet data

The system SHALL NOT bundle any pre-defined planet configuration.

Scenario: Inspect geo-planet exports

• WHEN all exports from @suaveplan/geo-planet are enumerated
• THEN no EARTH, MARS, or pre-built PlanetConfig constant exists