Fetching TLEs

This package defines a simple API to fetch TLEs from different sources. For more information, see the file API.md in the directory ./src/fetcher/.

It already contains the support to Celestrak. To fetch TLEs from this source, we first need to create the fetcher object:

julia> f = create_tle_fetcher(CelestrakTleFetcher)CelestrakTleFetcher: https://celestrak.org/NORAD/elements/gp.php

Afterward, we can fetch the TLEs using the function fetch_tles:

julia> fetch_tles(f, satellite_name = "AMAZONIA 1")[ Info: Fetching TLEs from Celestrak using satellite name "AMAZONIA 1"...
1-element Vector{TLE}:
 TLE: AMAZONIA 1 [47699] (Epoch = 2026-09-07T10:49:09.932)

This function will always return a Vector{TLE}, which is empty if no TLE matches the query.

For Celestrak fetcher, the following options are available:

• international_designator::Union{Nothing, AbstractString}: International designator using the format YYYY-NNN or YYYY-NNNP, where YYYY is the launch year, NNN is the launch number, and P is the piece of the launch. (Default: nothing)
• satellite_number::Union{Nothing, Integer}: Satellite catalog number (NORAD). (Default = nothing)
• satellite_name::Union{Nothing, AbstractString}: Satellite name. Notice that the system will search for all satellites whose name contains this string. (Default: nothing)

Thus, if we want to know, for example, all the satellites that were launched by the same rocket, we can search by the international designator as follows:

julia> fetch_tles(f, international_designator = "2021-015")[ Info: Fetching TLEs from Celestrak using international designator "2021-015"...
2-element Vector{TLE}:
 TLE: AMAZONIA 1 [47699] (Epoch = 2026-09-07T10:49:09.932)
 TLE: OBJECT B [47700] (Epoch = 2026-09-07T13:23:34.295)

If the request fails, for example because the service is unreachable, the function throws a TleFetchError with the URL and, if available, the HTTP status of the request.