OrbitalWiki vs CelesTrak
The long-running public source for orbital element sets and the satellite catalog, run as a non-profit. No account, no key, and the files are updated continuously.
CelesTrak is upstream of this catalog. We read its data, we do not replace it. For the authoritative figures, go to CelesTrak directly. See every source
Side by side with CelesTrak
| Feature | OrbitalWiki | CelesTrak |
|---|---|---|
| Run by | OrbitalWiki | Dr. T.S. Kelso, CelesTrak (501(c)(3) non-profit) |
| Account required | No | No |
| Machine-readable API | Yes | Yes |
| Bulk download | Yes | Yes |
| Free limit | No key needed to read; 1,000 requests a day with a free key | No published number; a usage policy applies |
| Data terms | ODbL-1.0, attribution required | CelesTrak usage policy |
| Per-field source shown | Yes | No |
Provider documentation checked 2026-08-03.
When to use CelesTrak instead
For the orbital elements themselves. CelesTrak is upstream of this catalog and updates faster than we do, so if you are propagating orbits, screening conjunctions, or you need the freshest element set, take it from CelesTrak. It also carries data we do not republish, including supplemental element sets and conjunction reports.
Go to CelesTrakWhen this catalog helps
When the question is about the object rather than its orbit. CelesTrak tells you where something is; it does not set out to reconcile who operates it against another catalog. If you need an operator name, a mission identity, or a record of where a value came from, that reconciliation is the part this site does.
Common questions
- Is OrbitalWiki a replacement for CelesTrak?
- No. CelesTrak is one of the sources this catalog is built from. It stays the better choice for orbital elements; this site adds identity and provenance on top of them.
- Does CelesTrak need an API key?
- No. CelesTrak serves its data files openly, with a usage policy asking you not to hammer the servers. There is no registration step.
- Can I redistribute CelesTrak data?
- CelesTrak publishes a usage policy that governs this. Read it before redistributing, and cite CelesTrak either way.