> ## Documentation Index
> Fetch the complete documentation index at: https://docs.rotastellar.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Templates

> Predefined orbit and constellation templates

<Note>
  **Base URL:** `https://sim.rotastellar.com`
  — No API key required.
</Note>

## Orbit Templates

`GET /v1/templates` returns predefined orbit profiles.

<RequestExample>
  ```bash Orbit Templates theme={null}
  curl https://sim.rotastellar.com/v1/templates
  ```

  ```bash Constellation Templates theme={null}
  curl https://sim.rotastellar.com/v1/constellation-templates
  ```

  ```bash Expand Constellation theme={null}
  curl -X POST https://sim.rotastellar.com/v1/constellation-templates/walker-star-6-3/expand \
    -H "Content-Type: application/json" \
    -d '{"base_orbit": "leo-standard"}'
  ```
</RequestExample>

<ResponseExample>
  ```json 200 Orbit Templates theme={null}
  [
    {
      "id": "leo-standard",
      "name": "LEO Standard",
      "altitude_km": 550,
      "inclination_deg": 53,
      "eccentricity": 0.0001,
      "description": "Standard low-Earth orbit at 550 km"
    },
    {
      "id": "leo-low",
      "name": "LEO Low",
      "altitude_km": 420,
      "inclination_deg": 51.6,
      "eccentricity": 0.0002,
      "description": "Low LEO at ISS altitude"
    },
    {
      "id": "sun-sync-500",
      "name": "Sun-Synchronous 500km",
      "altitude_km": 500,
      "inclination_deg": 97.4,
      "eccentricity": 0.0001,
      "description": "Dawn-dusk sun-synchronous orbit"
    },
    {
      "id": "sun-sync-700",
      "name": "Sun-Synchronous 700km",
      "altitude_km": 700,
      "inclination_deg": 98.2,
      "eccentricity": 0.0001,
      "description": "Higher sun-synchronous orbit"
    },
    {
      "id": "polar-800",
      "name": "Polar 800km",
      "altitude_km": 800,
      "inclination_deg": 98.7,
      "eccentricity": 0.0001,
      "description": "Near-polar orbit"
    },
    {
      "id": "meo-navigation",
      "name": "MEO Navigation",
      "altitude_km": 20200,
      "inclination_deg": 55,
      "eccentricity": 0.001,
      "description": "Medium Earth orbit (GPS/Galileo)"
    },
    {
      "id": "geo-comms",
      "name": "Geostationary",
      "altitude_km": 35786,
      "inclination_deg": 0,
      "eccentricity": 0.0001,
      "description": "Geostationary orbit"
    }
  ]
  ```

  ```json 200 Constellation Templates theme={null}
  [
    {
      "id": "walker-star-6-3",
      "name": "Walker Star 6/3/1",
      "satellite_count": 6,
      "planes": 3,
      "sats_per_plane": 2,
      "base_orbit": "leo-standard",
      "description": "6 satellites across 3 orbital planes"
    },
    {
      "id": "walker-star-12-4",
      "name": "Walker Star 12/4/1",
      "satellite_count": 12,
      "planes": 4,
      "sats_per_plane": 3,
      "base_orbit": "leo-standard",
      "description": "12 satellites across 4 planes"
    },
    {
      "id": "polar-ring-4",
      "name": "Polar Ring",
      "satellite_count": 4,
      "planes": 2,
      "sats_per_plane": 2,
      "base_orbit": "sun-sync-500",
      "description": "4 satellites in 2 sun-synchronous planes"
    },
    {
      "id": "single-plane-3",
      "name": "Single Plane Trio",
      "satellite_count": 3,
      "planes": 1,
      "sats_per_plane": 3,
      "base_orbit": "leo-standard",
      "description": "3 satellites in a single plane"
    }
  ]
  ```
</ResponseExample>

## Expand Constellation

`POST /v1/constellation-templates/:id/expand` generates per-satellite orbital elements from a constellation template.

<ParamField body="base_orbit" type="string">
  Override the template's base orbit. Must be a valid orbit template ID (e.g., `leo-standard`, `sun-sync-500`).
</ParamField>

The response includes an `orbits` array with fully resolved orbital elements for each satellite, including computed RAAN spacing and mean anomaly offsets.