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SpacePings vs Heavens-Above
The web's most thorough free satellite-prediction site, and a native iOS app built around one moment it doesn't call. Here's the honest difference.
Heavens-Above is a free website that hands you a table: rise time, peak time, set time, direction, and brightness for every satellite pass worth watching over your location, for the next several nights. It's been doing this since before smartphones existed, still maintained by its original author, and it remains one of the most thorough free satellite resources on the open web -- daily predictions for the brightest satellites, ten-day predictions for the ISS, Starlink, and the Chinese space station specifically, a genuinely large satellite database beyond just those, plus interactive sky charts, live sky views, and 3D orbit displays. If what you want is the deepest catalog of what's up there and when, in one place, for free, this is a real, credible tool -- not a toy.
What it doesn't do is come to you. You type in your location, pick a satellite, and read a table; nothing pushes a notification to your phone when a good pass is about to start. Its own mobile page describes a browser-based mobile version -- "runs on any device with an HTML5 capable browser" -- rather than a dedicated app; there's a separate official Android app for that, but no iOS app. On iOS, Heavens-Above means a bookmark and a habit of checking it, not a ping.
| Feature | SpacePings | Heavens-Above |
|---|---|---|
| Push notification before a pass | Yes -- free tier, one push per pass that clears the quality gate (30°+ peak elevation, dark enough sky, forecast clear enough) | No -- it's a predictions table you check yourself; the site has no alert system |
| Calls the exact Fade / ignition moment | Yes -- a live countdown to the second the satellite crosses into Earth's shadow, plus a haptic buzz 10 seconds out | No -- the pass table lists start, peak, and end times only; no shadow-crossing moment is called |
| Cloud-aware alerting | Yes -- a pass alert only fires if the forecast cloud cover for that hour is under 40% | N/A -- there's no alert to gate; the table doesn't factor in weather |
| Satellite catalog depth | ISS, Starlink trains, and other bright naked-eye passes, plus launches worth watching | Extensive -- ISS, the Chinese space station, Starlink, a much larger satellite database, plus comets, asteroids, planets, and full interactive sky charts |
| Platform | Native iOS app | Free website, usable from any mobile browser including iOS; a separate official Android app also exists -- no dedicated iOS app |
| Price | Free tier (push alerts, full quality gate, tonight's sky, 1 location); Pro $4.99/mo or $29.99/yr for multi-location and custom lead times | Free |
The other gap is the one this whole site is built around. Heavens-Above's own pass table is honest and precise about start, peak, and end times -- but "end" on a real pass sometimes isn't the satellite setting below your horizon. It's the satellite flying out of sunlight and into Earth's own shadow, mid-sky, while it's still climbing or high overhead. That's the Fade, and no table cell captures the fact that something is about to visibly vanish in front of you in the next few seconds. SpacePings' whole notification design exists to call that one moment: a push before the pass, a countdown that ticks down to it, and a haptic buzz ten seconds out, timed to within about ten seconds of the real event given the physics involved.
If a full catalog and total control over what you look up is what you want, Heavens-Above earns its reputation. If you want one honest push before the good ones and a call at the exact second the sky does something worth watching, that's what SpacePings pings for -- free on iOS, no account needed to check tonight's sky.