: For users of the Guide planetarium software, official updates and satellite identification files (like all_tle.txt ) are provided on the Project Pluto Update Page .

: Because satellite orbits decay or change, it is recommended to download a fresh version of these files every one to two weeks to maintain accuracy.

: This is the authoritative source for Two-Line Element (TLE) sets for all cataloged satellites. You can register for a free account at Space-Track to download custom satellite text files.

: Files with naming conventions like ndasat (often a contraction for "NASA data satellite") usually contain TLE data used to calculate the real-time position of satellites in the sky.

: A widely used alternative for current satellite orbital elements. You can browse and download grouped satellite data (e.g., GPS, weather, or communication satellites) in .txt format at CelesTrak . General File Information