Data Sources

Craft aggregates data from over a dozen sources to build a unified picture of what is happening above your location. This page documents where each type of data comes from and links you to the original sources so you can explore them directly.

Tip

Every source listed here is free to access. Some (like Space-Track) require a free account. None require payment.

Orbital Data

These sources provide the orbital elements that Craft uses to compute satellite positions, predict passes, and render trajectories on the globe.

Source	Craft uses it for	Explore
CelesTrak	TLE data for 22,000+ active satellites, rocket bodies, and debris	Primary TLE source, maintained by Dr. T.S. Kelso
Space-Track.org	Official USSPACECOM catalog data (free account required)	The authoritative upstream source for US-tracked objects
JPL Horizons	Planetary, asteroid, and comet ephemerides via Skyfield	Query any solar system body’s position across time
Minor Planet Center	Comet orbital elements	IAU clearinghouse for small body observations

Note

CelesTrak redistributes Space-Track data with additional group classifications (amateur, weather, Starlink, etc.) that Craft uses for filtering and search. If you configure SPACETRACK_USER and SPACETRACK_PASS in your .env, Craft will also pull directly from Space-Track for supplementary data.

Space Environment

Solar activity drives everything from radio propagation to satellite drag. Craft monitors these sources to give you a picture of current space weather conditions alongside your tracking data.

Source	Craft uses it for	Explore
NOAA SWPC	Solar flux (F10.7), K-index, geomagnetic storms, aurora forecasts, WWV propagation	The definitive source for operational space weather
HAMQSL Solar Page	HF propagation conditions at a glance	Quick visual summary popular with ham operators
NASA NEO API	Near-Earth object close approaches	Browse upcoming asteroid flybys with distance and size
CelesTrak SOCRATES	Conjunction (close approach) alerts between tracked objects	See which satellites are passing dangerously close to each other

Atmospheric & RF Environment

Observing conditions depend on more than just orbital mechanics. Cloud cover, wind, and nearby radio activity all matter. Craft pulls from these sources to help you plan observations and understand your RF environment.

Source	Craft uses it for	Explore
Open-Meteo	Cloud cover, visibility, wind speed, temperature at observer location	Free weather API with no key required
OpenSky Network	Live ADS-B aircraft positions near observer	Crowdsourced flight tracking with open data access
SondeHub	Radiosonde positions and telemetry	Community network of volunteer radiosonde receivers
IGRA	Upper-atmosphere sounding data (complementary)	Decades of radiosonde observations from NOAA NCEI

Note

Open-Meteo deserves special mention — it provides accurate weather data with no API key, no rate limit headaches, and no cost. Craft uses it for cloud cover forecasts so you know whether a visible satellite pass is actually worth going outside for.

Launches & Events

Knowing what just launched or what is about to reenter helps you make sense of new objects appearing in the catalog and old ones disappearing.

Source	Craft uses it for	Explore
Launch Library 2	Upcoming and recent launches, launch vehicle details, astronaut information	Community-maintained launch database with a clean API
Aerospace Corporation	Reentry predictions for decaying objects	Tracks large objects expected to survive reentry

CelesTrak The backbone of Craft's orbital data. Dr. T.S. Kelso has maintained this service since 1985 -- it is an institution in the satellite tracking community.

NOAA SWPC Space weather forecasts, alerts, and historical data. If you are wondering why HF propagation is terrible today, this is where you find out.

The Space Devs The team behind Launch Library 2. Their API powers launch tracking in Craft and dozens of other space-related applications.