> ## 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.

# Inject Fault

> Injects a fault into a satellite within a simulation session

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

### Path Parameters

| Parameter   | Type   | Description                                 |
| ----------- | ------ | ------------------------------------------- |
| `sessionId` | string | The session ID returned from Create Session |

### Fault Types

| Type                 | Description                                                  |
| -------------------- | ------------------------------------------------------------ |
| `power_loss`         | Reduces available power generation                           |
| `thermal_exceedance` | Raises subsystem temperature beyond nominal range            |
| `radiation_upset`    | Simulates single-event upset from radiation                  |
| `comms_failure`      | Degrades or disables communication links                     |
| `isl_degradation`    | Reduces inter-satellite link bandwidth and increases latency |

<RequestExample>
  ```bash theme={null}
  curl -X POST https://sim.rotastellar.com/v1/sessions/ses_abc123/fault \
    -H "Content-Type: application/json" \
    -d '{
      "satellite_id": "sat-001",
      "fault_type": "power_loss",
      "severity": 0.8
    }'
  ```
</RequestExample>

<ResponseExample>
  ```json 200 OK theme={null}
  {
    "session_id": "ses_abc123",
    "satellite": {
      "id": "sat-001",
      "name": "RS-LEO-1",
      "position": { "lat_deg": 33.8, "lon_deg": -114.5, "alt_km": 548.6 },
      "sunlit": true,
      "subsystems": {
        "power_w": 23,
        "thermal_c": 22.6,
        "comms_dbm": -81,
        "memory_used_mb": 1028
      },
      "faults": [
        {
          "type": "power_loss",
          "severity": 0.8,
          "injected_at": "2026-03-10T12:06:00Z",
          "effect": "power_generation reduced by 80%"
        }
      ]
    }
  }
  ```
</ResponseExample>