How SpaceTracker.live works

Earth-orbit satellites

The server retrieves current GP/OMM orbital records from CelesTrak and caches them. Your browser uses satellite.js with SGP4/SDP4 propagation to calculate current Earth-centered positions, latitude, longitude, altitude and velocity.

Your observing location

When you choose a location, the browser calculates azimuth, elevation, range and seven-day geometric passes relative to those coordinates. Device geolocation is requested only after you press the location button. Manual coordinates are also supported.

Deep-space missions

Voyager, JWST and interplanetary missions are not treated as ordinary Earth satellites. Their current vectors are obtained from NASA/JPL Horizons and cached server-side. The deep-space scene uses a compressed visual scale; the numerical ephemeris values are the authoritative display.

Geometric versus visible passes

A geometric pass means an Earth-orbiting spacecraft is above the mathematical horizon. It is not automatically an optical sighting opportunity. Illumination, darkness, magnitude, clouds, terrain and local conditions affect visibility.