CelesTrak Satellite TLE Scraper — Orbital Elements API

Pull current orbital elements (TLE / GP data) for active satellites from CelesTrak, the de facto public source for satellite tracking data used by amateur radio operators, space situational awareness teams, ground-station networks, and educational institutions worldwide.

What this Actor does

This Actor wraps CelesTrak's gp.php JSON endpoint and returns enriched, structured orbital element records for the satellite group you choose. It computes derived fields (semi-major axis, altitude, orbital period) so the data is ready to drop into an SGP4 propagator or a tracking dashboard.

Use cases:

• Ground station scheduling: Pull the latest Starlink, Iridium, or weather satellite TLEs for pass prediction.
• Aerospace & defense analytics: Feed orbital element snapshots into space-debris monitoring or conjunction analysis pipelines.
• Educational tooling: Build a classroom satellite tracker without scraping HTML.
• AI / ML: Build a training corpus of orbital regimes for anomaly detection models.

How to scrape CelesTrak satellite data

1. Pick a Satellite Group keyword (default stations for the ISS + CSS, always small and reliable). Common groups: starlink, gps-ops, galileo, glo-ops, beidou, weather, noaa, science, geo, iridium-NEXT, oneweb, planet, spire, active.
2. Optionally filter by Name (partial match) or by a comma-separated list of NORAD Catalog IDs.
3. Set Max Results (default 1,000).
4. Run.

Output fields

Field	Description
objectName	Satellite name (e.g. "ISS (ZARYA)")
objectId	International designator (COSPAR ID)
noradCatId	NORAD catalog number
epoch	Epoch of the orbital element set (ISO 8601 UTC)
meanMotion	Mean motion (rev/day)
eccentricity	Orbital eccentricity
inclination	Orbital inclination (degrees)
raOfAscNode	RAAN (degrees)
argOfPericenter	Argument of pericenter (degrees)
meanAnomaly	Mean anomaly (degrees)
bstar	BSTAR drag term
meanMotionDot / meanMotionDdot	1st / 2nd time derivatives of mean motion
ephemerisType / classificationType	TLE bookkeeping fields
elementSetNo / revAtEpoch	Element set number, revolution at epoch
semiMajorAxisKm	Derived from mean motion
altitudeKm	Approximate altitude above Earth's surface (semi-major axis − Earth radius)
periodMinutes	Orbital period
group	The CelesTrak group keyword used
sourceUrl	The exact CelesTrak URL queried

Pricing

Pay-per-result. CelesTrak rate-limits requests; this Actor makes a single batched call per run, so each invocation is fast and friendly.

Example input

{
  "group": "starlink",
  "nameFilter": "",
  "maxResults": 2000
}

Example output (single record)

{
  "objectName": "ISS (ZARYA)",
  "objectId": "1998-067A",
  "noradCatId": 25544,
  "epoch": "2026-05-15T03:12:11.118",
  "meanMotion": 15.49,
  "eccentricity": 0.00041,
  "inclination": 51.64,
  "altitudeKm": 414.2,
  "periodMinutes": 92.96,
  "group": "stations"
}

FAQ

Q: Where do TLEs come from? CelesTrak aggregates them from Space-Track / 18 SDS publications. Some commercial constellations also publish their own ephemerides.

Q: How fresh is the data? Element sets typically update multiple times per day for LEO satellites. The epoch field tells you the exact age of each record.

Q: How do I propagate the orbit? Use any SGP4 library (e.g., satellite.js in Node, sgp4 in Python) and pass the classical elements directly.

Q: What happens if I pick a group with no satellites? The Actor logs a warning and exits cleanly with zero results. Try active to dump all ~10,000 tracked objects.

Legal disclaimer

This Actor accesses the public CelesTrak gp.php JSON endpoint. CelesTrak's terms allow non-commercial and limited commercial use; for bulk commercial reuse, please review CelesTrak's usage policy. Not affiliated with or endorsed by CelesTrak or T.S. Kelso.