Scenario kind pagesEdit on GitHubSource: docs/kinds/by-kind/launch-window.md

launch-window (scenario kind)

Scenario kind of the engine v0.38.0, family Mission analysis, links and space operations. Advisory: analysis output from a research and engineering tool, not type-approved navigation equipment and not a safety-of-life service. Every label here is the engine's or the verification matrix's; a kind is MODELLED unless the matrix says otherwise (how a label is earned: the README's Evidence section).

What it does#

Two-body launch & ascent geometry: launch azimuth(s) (sin Az = cos i / cos lat), minimum reachable inclination, circular velocity, the Earth-rotation eastward bonus, dogleg plane-change Δv when the target inclination is below the site latitude, and the number of daily launch opportunities. MODELLED spherical-Earth geometry (no rotating-Earth velocity-triangle correction, no ascent/drag-loss model).

One run of scenarios/launch-window.toml summarises as: launch-window: lat 28.5° -> i 51.6°: Az 45.0° asc, v_circ 7669 m/s, +409 m/s Earth-rotation bonus, 2 opportunities/day (MODELLED)

Inputs#

From the schema (kshana kinds --json):

  • Required fields: none
  • Optional fields: site_lat_deg, target_inclination_deg, altitude_km, site_lon_deg, epoch, eop_finals2000a

The example scenarios/launch-window.toml sets, among others:

Field Value Unit
altitude_km 400 km
kind launch-window text
site_lat_deg 28.5 deg
target_inclination_deg 51.6 deg

Run it#

kshana scenarios/launch-window.toml

What it gives#

The scalar results of that run, with the units the engine states:

Result Value Unit
altitude_km 400 km
circular_velocity_m_s 7668.558175 m/s
daily_opportunities 2 count
dogleg_plane_change_dv_m_s no value m/s
epoch no value not stated
launch_azimuth_deg.ascending 44.975133 deg
launch_azimuth_deg.descending 135.024867 deg
min_inclination_deg 28.5 deg
site_lat_deg 28.5 deg
site_lon_deg 0 deg

Result label (the engine's): MODELLED — two-body spherical-Earth launch geometry; azimuth is the geometric sin(Az)=cos(i)/cos(lat) relation (no rotating-Earth velocity-triangle correction, no ascent/drag-loss model)

The chart the engine writes for scenarios/launch-window.toml, kind launch-window

Evidence#

MODELLED: the verification matrix rows that name this kind.

  • MODELLED Two-body launch azimuth(s) (sin Az = cos i / cos lat), minimum reachable inclination, circular velocity, Earth-rotation eastward bonus, dogleg plane-change Δv and daily opportunities, and, given an epoch and IERS finals2000A rows, the site

The rows the run itself exercised, with the oracle the matrix gives each (the public sources are named there):

  • MODELLED Deterministic, scenario-hashed, SBOM + cross-platform golden gates. Oracle (ExternalDataset): SBOM conformance to the official CycloneDX 1.5 JSON Schema (+ valid SPDX identifiers) — an external published standard, zero validation errors over the full dependency graph; the FoM-determinism / byte-reproducibility part remains a pinned self-consistency check, so the row stays MODELLED
  • MODELLED Two-body launch azimuth(s) (sin Az = cos i / cos lat), minimum reachable inclination, circular velocity, Earth-rotation eastward bonus, dogleg plane-change Δv a. Oracle (InternalConsistency): Closed-form spherical-trig launch geometry vs published worked-example anchors (Vallado, Fundamentals of Astrodynamics 4th ed., Algorithm 37 launch-azimuth + Ch.6 plane-change; tests/launch_window_ascent_geometry_reference.rs). These re-use the same closed form kshana implements (a published-value parity / transcription check, InternalConsistency); MODELLED two-body, no rotating-Earth velocity-triangle / ascent / dra

Limitations#

What the run's own report says is not modelled or not validated:

  • MODELLED — two-body spherical-Earth launch geometry; azimuth is the geometric sin(Az)=cos(i)/cos(lat) relation (no rotating-Earth velocity-triangle correction, no ascent/drag-loss model) (result label)
  • MODELLED spherical-Earth geometry (no rotating-Earth velocity-triangle correction, no ascent/drag-loss model). (kind catalogue (kshana kinds --json))
  • HONEST SCOPE: MODELLED. Geometric azimuth only -- no rotating-Earth velocity-triangle correction (the bonus is reported separately to fold in), no ascent trajectory / drag-loss / steering model. Pre-Phase-A geometry. Run: kshana scenarios/launch-window.toml (scenario file comment, lines 8 to 11)
  • Reproducibility & software assurance is MODELLED, not validated: a sub-claim is externally checked, but the whole capability composes modelled pieces, so the capability stays Modelled. (verification matrix (docs/MODELLED-RATIONALE.md))
  • Launch-window & ascent geometry (mission analysis) is MODELLED, not validated: checked against its own closed-form / analytic identity — catches transcription and coefficient errors, but is not an external oracle. (verification matrix (docs/MODELLED-RATIONALE.md))

See also#