CelesTrak

CelesTrak is an online data resource that provides publicly accessible orbital information and tracking tools for artificial satellites. The site aggregates and distributes standard orbital data, including two-line element sets, satellite catalogs, and constellation feeds, which are widely used by researchers, educators, hobbyists, and satellite operators to compute ephemerides and plan observations.

Two-line element sets (TLEs) are the core data format on CelesTrak. When used with orbital models such as SGP4 or SDP4, TLEs enable propagation of satellite positions to generate predicted passes and visibility windows. The site also hosts catalogs like SatCat and various feeds categorized by operator or mission.

Access to the data is free and straightforward, with files available for download and, in many cases, direct integration via software. Users rely on CelesTrak to obtain up-to-date orbital elements and to verify data against other sources. The resource is commonly cited in the satellite-tracking community and in educational contexts.

Overall, CelesTrak serves as a practical reference and data distribution point that supports space situational awareness, ground-station planning, and hobbyist observation by providing reliable, regularly updated orbital data in standard formats.