Open Notify

Overview

Open Notify serves real-time data about the International Space Station: who’s currently in space, the ISS’s current position, and when it passes over a location. Free, keyless, and a fun data source for space-themed apps and science demos.

Quick Start

People currently in space (verified live):

curl "http://api.open-notify.org/astros.json"

{
  "number": 7,
  "people": [
    { "craft": "ISS", "name": "Oleg Kononenko" },
    { "craft": "ISS", "name": "Nikolai Chub" }
  ],
  "message": "success"
}

ISS current position (lat/lon):

curl "http://api.open-notify.org/iss-now.json"

Next ISS pass over a location:

curl "http://api.open-notify.org/iss-pass.json?lat=36.72&lon=-4.42"

Authentication

None — keyless.

Rate Limits & Notes

• Free; no hard documented limit — be polite (it’s a small volunteer service).
• Only HTTP is available (no HTTPS on the API host) — avoid sending it sensitive data.
• ISS position updates every few seconds; pass predictions are approximate.
• The service occasionally has downtime — cache responses in production apps.

FAQ

Is Open Notify free? Yes — free and keyless.

Why is it HTTP only? The API host doesn’t offer HTTPS — fine for public data, just don’t pass secrets.

How accurate is the ISS position? Updated every few seconds from public tracking data — good enough for displays, not for navigation.