How it works

The International Space Station orbits Earth roughly every 90 minutes at about 28,000 km/h. ISSINFO uses the same SGP4 orbital propagation algorithm relied on by NORAD and NASA to calculate exactly where the station is — and where it will be.

When you open the app it downloads the latest Two-Line Element (TLE) data from our API, then runs all the orbital maths on your device. That means the map updates smoothly in real time and pass predictions keep working even when you have no internet connection.

Your location is used once — to work out which passes will be visible from where you are. It is never sent to a server.

How the map works

The tracking map shows the ISS moving over Earth in real time with a 24-hour ground track behind it. A day/night terminator overlay lets you see at a glance whether the station is in sunlight or shadow — important because you can only see the ISS when it is sunlit and you are in darkness or twilight.

How pass predictions work

ISSINFO calculates every pass over your location for the coming days. Each pass shows the start time, duration, maximum elevation, and compass direction so you know exactly when and where to look. Passes are filtered to only show ones you can actually see with the naked eye, and the best opportunities are highlighted with a “Great Pass” label.

Features

Live ISS Map

Real-time tracking map with ground track, coordinates, altitude, velocity, and day/night overlay.

Pass Predictions

Exactly when the ISS will fly over you — start time, duration, max elevation, and compass direction.

Meet the Crew

Photos, bios, and agency info for every astronaut currently aboard the station.

AR Sky Compass PRO

Point your phone at the sky during a pass and an AR overlay guides you straight to the station.

Pass Notifications PRO

Push notification before each visible pass. Choose which passes to be alerted for with a single tap.

Cloud Cover Forecast PRO

See the cloud cover forecast for each pass so you know whether skies will be clear.

Works Offline

All orbital maths runs on-device. Tracking and predictions work without internet for up to 48 hours.

Designed for iPad too

ISSINFO is a universal app optimised for both iPhone and iPad. The larger screen gives you more room for the map, richer crew details, and a wider view of your upcoming passes.

Free and Pro

ISSINFO is free to download and use. The live map, 5 days of pass predictions, and the full crew list are included at no cost.

Subscriptions auto-renew and can be cancelled at any time in your device Settings.

Your privacy, taken seriously

We built ISSINFO with a privacy-first approach. Here is exactly what the app does — and does not do.

No analytics

There are no analytics frameworks in the app. No Firebase, no Amplitude, no tracking pixels. We do not collect usage data, session data, or behavioural data of any kind.

No third-party SDKs

The app is built entirely with Apple frameworks — SwiftUI, MapKit, ARKit, WeatherKit, StoreKit. There are no third-party libraries or SDKs. No code from ad networks, analytics providers, or data brokers runs on your device.

Location stays on your device

Your location is used only to calculate pass predictions. It is processed entirely on-device and is never transmitted to our servers or any third party. The app requests “When In Use” permission only — it never tracks you in the background.

Camera is used only for AR

The camera is accessed only when you open the AR Sky Compass view during a pass. No images or video are recorded, stored, or transmitted. The camera feed is processed in real time by ARKit on your device and discarded immediately.

Orbital calculations are local

The SGP4 propagation algorithm runs on your device. The only network requests the app makes are to our own API (api.issinfo.net) to fetch TLE orbital data, ISS position history, and crew information. No personal data is included in these requests.

Notifications are local

Pass notifications are scheduled locally on your device using Apple's notification system. No push notification service or external server is involved.

Subscriptions through Apple

All payments are handled by Apple's App Store. We never see or store your payment information.

Technical Details

• Built with Swift 6 and SwiftUI
• Targets iOS 26 / iPadOS 26
• SGP4 orbital propagation in pure Swift
• 4 Hz map updates, 60 fps interpolation
• On-device pass prediction
• TLE data cached 48 hours for offline use
• Apple WeatherKit for cloud cover
• ARKit + CoreMotion for sky compass
• Universal — iPhone and iPad