ORBITAL Satellite Tracker

A single-file browser app that renders real-time satellite positions on a 3D globe.

What it does

Pick any satellite from the catalog, hit SHOW, and watch its orbit ellipse appear on the globe. The dot moves in real time. Scrub the timeline forward or backward up to 12 hours, toggle ground tracks, and inspect live telemetry (lat/lon/altitude/velocity/period) in the side panel.

How it works

TLE data is fed into the SGP4 propagation model via satellite.js. Orbit math runs in a pool of Web Workers so the UI never blocks. Cesium renders the 3D globe in an inertial (ICRF) reference frame -- meaning the orbit ellipse stays fixed in space while the Earth rotates underneath it, which is physically correct. Ground tracks are computed geodetically and split at the anti-meridian. No backend, no build step.

What you need

TLE files. The app ships with a small built-in catalog (ISS, GPS, weather sats, etc.), but for anything current you need fresh TLEs — drag-and-drop a .tle / .txt file onto the globe, or grab one from Celestrak or Space-Track.

Caveats

TLEs expire. A TLE is only accurate for a short window around its epoch -- typically 1 to 3 days for LEO, longer for high orbits. Positions shown for stale TLEs will drift from reality. Re-download regularly if accuracy matters.

Disclaimer

Yes, this is mostly AI slop, but it fulfills its purpose which is figure out when a METEOR-M satellite passes so we can attempt to receive imagery. Contact volker@cheleb.net if you care to improve or unslop.