# OrbitalMap > A live map of near-Earth orbit built from public data: satellites, launches, > spaceports and the weather over the pads. A static single-page app with no > backend of its own - every position is computed in the reader's own browser > from data fetched directly from the public sources below. OrbitalMap runs no application server and stores nothing about its readers. With one exception, named in the next paragraph, it does not host, proxy or republish the source data either: the browser talks to each public API directly, works out positions and forecasts locally, and keeps nothing on a server. There is no OrbitalMap-operated API to call instead - the sources listed below are the primary data, and each one carries its own licence. The exception is the orbital catalogue. Fetching thirty themed files from CelesTrak on every page load is the shape of use its own usage policy asks sites not to have, so once a day the whole catalogue is collected, merged and published as two static files that the page then reads: ``` https://www.orbitalmap.space/mirror/catalogue.json.gz every element, OMM JSON, gzipped https://www.orbitalmap.space/mirror/groups.json.gz which themed file each object is in ``` That is a cache of open US government data (18 SDS/USSF, via CelesTrak) and not a dataset of our own: no field is added, invented or corrected, and CelesTrak's usage policy explicitly asks organisations to set up exactly this kind of proxy. It holds the present day only - there is no history behind it - and if it fails the page falls back to fetching each group from CelesTrak, as it did before the mirror existed. A second view leaves the planet: the solar system, with the spacecraft flying between the planets and beyond them. Directions in it are exact and distances are not - the range from Parker Solar Probe's perihelion to Voyager 1 is 3700 to 1, so each distance from the Sun is compressed by a square root, and the view carries no scale bar. Every figure the view quotes in kilometres, astronomical units or light travel time is the true one, taken from the trajectory before the projection touches it. Those trajectories are the one exception to the "fetched in the browser" rule above: JPL Horizons sends no CORS header, so they are baked into the site at build time and refreshed weekly. ## Licensing Every source has its own terms, and they are not uniform: some are public domain, some require attribution, and a couple state no licence at all (in which case they are read, not redistributed). The full, current list - what each source is used for, its licence, and any attribution it requires - is rendered in the app's "Sources and licences" panel (the `credits-modal` in `index.html`, built from `src/core/credits.ts`). Treat that page as the authoritative licence statement rather than any summary here, including this one. Do not assume a source is reusable just because OrbitalMap reads it: several carry non-commercial or unstated terms and are shown for the reader only. The whitelist OrbitalMap itself applies before treating any image as reusable lives in `src/core/licence.ts` (`reusableCommercially`). ## Key sources (see credits.ts for the full, current list and licences) - CelesTrak (18 SDS/USSF GP catalogue) - satellite orbital elements - open US government data. - GCAT (Jonathan C. McDowell) - spaceports, spacecraft shapes, owners - CC BY 4.0, citation required. - NASA EOSDIS GIBS / Worldview - Earth imagery and cloud - public domain (US government), no implied endorsement. - CNEOS Fireballs (NASA/JPL) - fireball events - public domain (US government). - JPL Horizons (NASA/JPL-Caltech) - deep-space mission and planet trajectories - public domain (US government); sampled at build time, and predicted rather than measured beyond the build date. - OpenStreetMap / Nominatim - reverse geocoding for "you are here" - ODbL 1.0, attribution required, requested only on explicit user action. - Launch Library 2 / Spaceflight News API (TheSpaceDevs) - launch schedule and news - licence not stated by the publisher; read only, not republished. - MET Norway - spaceport weather - NLOD / CC BY 4.0, attribution required. ## Pages - / (and /de/, /et/, /es/, /fr/, /uk/, /ko/, /ja/): the app itself, in English, German, Estonian, Spanish, French, Ukrainian, Korean and Japanese. What is selected is carried in the query - ?world=mars, ?world=solar-system&focus=voyager-1, ?sat=25544 - so a link is shareable, but the document served is the same one whatever it says. - /o/ (and /de/o/, /et/o/, /es/o/, /fr/o/, /uk/o/, /ko/o/, /ja/o/): an index of every object the site has written something of its own about. - /o//: one page per object - the planets, the dwarf planets, the asteroids and comets that have been visited, and the deep-space craft. The paragraph on each is written for this site and translated into every language the site is published in; it is the same text the app shows when you select the object on the map, so there is one copy of it and not two. Ids are the ones used in the query above: /o/mars/, /o/voyager-1/. The full list of addresses, with their language alternates, is in /sitemap.xml. ## For automated and AI agents Crawling and indexing this site is welcome; see `/robots.txt`. The one path disallowed there is `/mirror/`, and only for crawl budget: the catalogue is a megabyte and a half of orbital elements with nothing in it to index, so asking crawlers to skip it costs them nothing and saves both sides the bytes. It stays public and unauthenticated either way. There is no public API and no feed. The only bulk data here is the daily catalogue mirror described at the top of this file - `/mirror/catalogue.json.gz` and `/mirror/groups.json.gz` - which exists so that readers of this page do not each hammer CelesTrak, and which is served from a CDN edge. It carries the current day only. If you want orbital elements, please take them from CelesTrak itself, which is the publisher and can say when they were last updated; if you take them from here, credit 18 SDS/USSF via CelesTrak, and do not treat the address as an API contract - it exists for this page and may change with it. For everything else, query the original sources directly rather than treating OrbitalMap as a data proxy.