International Space Station Pass Predictions

GET /iss/v1/
GET /iss/
GET /iss-pass.json

The international space station (ISS) is an orbital outpost circling high above out heads. Sometimes it’s overhead, but when? It depends on your location. Given a location on Earth (latitude, longitude, and altitude) this API will compute the next n number of times that the ISS will be overhead.

Overhead is defined as 10 degrees in elevation for the observer. The times are computed in UTC and the length of time that the ISS is above 10 degrees is in seconds.

This gives you enough information to compute pass times for up to several weeks, but beware! times are less and less accurate as you go into the future. This is because the orbit of the ISS decays unpredictably over time and because station controllers periodically move the station to higher and lower orbits for docking, re-boost, and debris avoidance.


The API returns a list of upcoming ISS passes for a particular location formatted as JSON.

As input it expects a latitude/longitude pair, altitude and how many results to return. All fields are required.

As output you get the same inputs back (for checking) and a time stamp when the API ran in addition to a success or failure message and a list of passes. Each pass has a duration in seconds and a rise time as a unix time stamp.

Status Codes:
Query Parameters:
  • lat – latitude in decimal degrees of the ground station. required Range: -90, 90
  • lon – longitude in decimal degress of the ground station. required Range: -180, 180
  • alt – altitude in meters of the gronud station. optional. Range: 0, 10,000
  • n – requested number of predictions. default: 5. May return less than requested
Response JSON Object:
  • message (str) – Operation status.
  • request (obj) – Parameters used in prediction
  • response (list) – List of predicted passes

Example Request:

GET /iss/v1/?lat=40.027435&lon=-105.251945&alt=1650&n=1 HTTP/1.1
Accept: application/json, text/javascript

Example Response:

HTTP/1.1 200 OK
Content-Type: application/json

  "message": "success",
  "request": {
    "altitude": 1650.0,
    "datetime": 1454475126,
    "latitude": 40.027435,
    "longitude": -105.251945,
    "passes": 1
  "response": [
      "duration": 525,
      "risetime": 1454475538