Ephem · a space-data platform
One dataset engine. Three surfaces. A free-tier stack that stays free.
Ephem consolidates the public space-data record — NOAA space weather, CelesTrak orbital elements, Launch Library 2 upcoming launches, NASA DONKI heliophysics events, JPL Horizons ephemerides — into one clean HTTP interface, one consumer-facing overhead map, and one enterprise debris-density feed.
Every response is enveloped: {source, fetched_at, valid_until, data}. Every source is verified weekly. Every page here was written by a person.
What is happening right now
| Measurement | Value | Interpretation | Updated |
|---|---|---|---|
| Planetary K index | — | unavailable — check /status | — |
| GOES long-band X-ray | ? | unavailable — check /status | — |
| Next launch (worldwide) | — | no upcoming launch in window | details → |
| Latest heliophysics event | — | no events in the last 30 days | — |
The three surfaces
§1 Overhead map — a consumer map for figuring out which satellites are passing over your address right now. Free, no login, no cookies, no dark patterns.
§2 Developer API — a single HTTP API for the sources above. Free tier is 1,000 requests per day. Paid tiers start at $29/month.
§3 Debris feed — an orbital-debris density feed with methodology transparency. Enterprise pricing.
Why Ephem
Public space data has always existed. What has not existed is one interface across it that treats developers, consumers, and enterprises as legitimate readers of the same underlying record. Every existing product either serves one audience well and the others poorly, or bundles them into a dashboard nobody wants.
The other reason: the space-data providers move their endpoints. Not once, not twice — every six months, a URL you were depending on returns 404. Ephem stabilises the interface so that when NOAA reorganises services.swpc.noaa.gov, the change lives in one place, gets verified within 24 hours, and ships as a normal deploy. Callers see the same response envelope on day 1 and day 1,000.