ISS Tracker

ISS Tracker follows the International Space Station in real time on a 3D globe. It shows where the station is right now, streams its live telemetry — altitude, velocity and ground-track coordinates — and works out when it will next pass over wherever you are.

The orbital core#

The interesting part isn't the map, it's the maths. The station's position comes from real TLE (Two-Line Element) data, which I propagate with satellite.js to compute the current sub-satellite point and ground track. Next-pass prediction takes any location you enter and searches forward for upcoming passes, and it goes a step further than "when" by working out whether you'll actually see it — a pass only counts as visible when the satellite is sunlit while your sky is dark, so the app checks that geometry rather than just reporting an overhead time.

The globe and the interface#

The globe is rendered with d3-geo, topojson-client and world-atlas land data, with the station and its track drawn on top. A telemetry panel keeps the live numbers in view, location lookup via geocoding lets you search by place name instead of typing coordinates, and a starfield backdrop and Framer Motion transitions give it a polished feel. Internal API routes (/api/tle, /api/track, /api/iss, /api/pass, /api/geocode) keep the orbital computation and third-party lookups server-side. It's built on Next.js 16 (App Router), React 19 and Tailwind CSS v4.