The satellite layer displays live orbital positions for over 2,000 active satellites. No API key is required — all data comes from publicly available Two-Line Element (TLE) sets published by CelesTrak.
How it works
The backend fetches the latest TLE catalog from CelesTrak and uses the SGP4 (Simplified General Perturbation 4) orbital mechanics model to propagate each satellite’s position forward to the current UTC time. Positions are recalculated every 60 seconds as part of the fast-tier scheduler.
SGP4 is the standard algorithm used by NORAD for tracking Earth-orbiting objects. It accounts for atmospheric drag, solar pressure, and Earth’s oblateness to produce accurate near-Earth orbital predictions.
Data source
| Source | Data | Update frequency | API key |
|---|
| CelesTrak | Active satellite TLE catalog | ~60s | No |
Mission-type classification
Each satellite is assigned a mission type based on its catalog name and associated metadata. The type determines the icon color on the map:
| Mission type | Color | Examples |
|---|
| Military reconnaissance | Red | KH-series, USA-series NRO satellites |
| SAR (Synthetic Aperture Radar) | Cyan | Sentinel-1, NISAR, RADARSAT |
| SIGINT | White | Lacrosse/Onyx, classified USA satellites |
| Navigation | Blue | GPS Block III, GLONASS-M, Galileo |
| Early warning | Magenta | SBIRS, DSP missile-warning satellites |
| Commercial imaging | Green | Planet Labs, Maxar, Airbus |
| Space station | Gold | ISS, Tiangong, Mir |
Red dots over your area of interest indicate military reconnaissance or SIGINT satellites that may be conducting collection passes. Overhead timing is visible from the satellite’s current track on the map.
Scale
- 2,000+ active satellites tracked simultaneously
- Positions are updated every 60 seconds
- Each satellite icon is oriented along its current ground track heading
The satellite layer is one of the densest on the map. To maintain smooth rendering at 2,000+ moving markers:
- The frontend uses imperative
setData() calls to update GeoJSON without triggering React re-renders
- A 2-second debounce prevents redundant GeoJSON rebuilds during pan/zoom
- Viewport culling with a 20% buffer limits rendering to visible satellites only
No API key required
CelesTrak publishes TLE data freely as part of its public space surveillance mission. ShadowBroker does not use any commercial space tracking APIs.
TLE data is published with a latency of a few hours relative to actual NORAD tracking. Propagated positions are accurate to within a few kilometers for low Earth orbit satellites.