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Pass Prediction API

The Pass Prediction API computes upcoming satellite passes from the configured observer location. Pass predictions include acquisition of signal (AOS), time of closest approach (TCA), and loss of signal (LOS) with azimuth and elevation at each point.

Predict Passes

Get all passes for a satellite within a time window.

GET /api/passes

Query Parameters

Parameter	Type	Default	Description
`sat`	`int`	—	NORAD catalog ID (required)
`hours`	`int`	`24`	Prediction window in hours (max 168 / 7 days)
`min_el`	`float`	`5.0`	Minimum peak elevation to include (degrees)

Response

{
  "observer": "Home QTH",
  "satellite": "ISS (ZARYA)",
  "norad_id": 25544,
  "passes": [
    {
      "satellite_name": "ISS (ZARYA)",
      "norad_id": 25544,
      "aos_time": "2026-02-14T23:15:00Z",
      "aos_az": 215.3,
      "tca_time": "2026-02-14T23:20:00Z",
      "tca_alt": 67.2,
      "tca_az": 145.8,
      "los_time": "2026-02-14T23:25:00Z",
      "los_az": 45.1,
      "duration_seconds": 600.0,
      "max_elevation": 67.2,
      "is_visible": true,
      "magnitude": -3.2
    }
  ],
  "count": 1
}

Pass Event Fields

Field	Type	Description
`satellite_name`	`string`	Satellite name
`norad_id`	`int`	NORAD catalog number
`aos_time`	`string`	Acquisition of signal (rise) time, ISO 8601
`aos_az`	`float`	Azimuth at AOS (degrees)
`tca_time`	`string`	Time of closest approach (max elevation), ISO 8601
`tca_alt`	`float`	Altitude at TCA (degrees)
`tca_az`	`float`	Azimuth at TCA (degrees)
`los_time`	`string`	Loss of signal (set) time, ISO 8601
`los_az`	`float`	Azimuth at LOS (degrees)
`duration_seconds`	`float`	Total pass duration in seconds
`max_elevation`	`float`	Peak elevation (degrees)
`is_visible`	`bool`	Whether the pass is optically visible
`magnitude`	`float\|null`	Estimated visual magnitude (if available)

Examples

# ISS passes in the next 24 hours, minimum 5 degrees elevation
curl "https://space.warehack.ing/api/passes?sat=25544"

# ISS passes in the next 72 hours, minimum 30 degrees elevation (high passes only)
curl "https://space.warehack.ing/api/passes?sat=25544&hours=72&min_el=30"

# NOAA-20 passes in the next 48 hours
curl "https://space.warehack.ing/api/passes?sat=43013&hours=48&min_el=10"

Next Pass

Get only the next upcoming pass for a satellite. This is a convenience endpoint that returns the soonest pass within the next 24 hours.

GET /api/passes/next

Query Parameters

Parameter	Type	Description
`sat`	`int`	NORAD catalog ID (required)

Response

Returns a single pass event (same shape as the items in the passes array above), or a message if no passes are found:

{
  "message": "No passes in next 24 hours"
}

Examples

# When is the next ISS pass?
curl "https://space.warehack.ing/api/passes/next?sat=25544"