EX01 — First Orbit

Tags: propagation · Walker constellation · ground track Input: first-orbit.yaml · Runtime tier: quick · Recommended views: 2D, 3D

Purpose

Use the smallest packaged example to learn the core RunSpec-to-artifact workflow. The engineering question is simply: where are the six satellites throughout one orbit, and what state evidence does Astraeus preserve?

Setup

The case propagates a six-satellite, two-plane Walker constellation at about 550 km and 53° inclination for 90 minutes at a 60-second reporting cadence.

astraeus run astraeus-resources/examples/user/first-orbit.yaml

Open the completed bundle in the Console and use the 2D ground-track and 3D constellation views.

RunSpec Focus

The key choice is the compact Walker layout. Requesting only propagation keeps the dependency graph and output bundle easy to inspect.

execution:
  stages: [propagation]
constellation:
  design:
    kind: walker
    orbit:
      kind: circular_altitude
      altitude_km: 550.0
      inclination_deg: 53.0
    layout:
      n_planes: 2
      n_sats_per_plane: 3

Results

The reference run completed successfully in 1.07 seconds. It produced 91 state samples for each of six satellites in TEME, with position and velocity arrays shaped 91 × 6 × 3. The reported fleet mean altitude was 542.73 km.

Artifacts To Inspect

Artifact	What it shows
run_manifest.json	Resolved stages, input hash, seed, versions, warnings, and final status
states/timeline_summary.json	Frame, propagator, cadence, satellite count, and array shapes
states/timeline_state_vectors_teme.parquet	Position and velocity for every satellite and timestamp

Interpretation

This case establishes the basic evidence chain: the RunSpec resolves the Walker layout, SGP4 propagates the generated orbital elements, and the manifest plus state artifacts make the result reproducible. Move to EX02 when the next question is visibility from Earth.