nostr:npub1vrlrf3pez9k0etcca5vchgr07d2vqgzelatmlv6tr5zx00ps3hss98khax TLE's change over time as ISS / satellites change orbit due to atmospheric drag, collision avoidance manoeuvres, orbital boosts to prevent orbit decaying etc

so every week or so you should update TLE's / Keplers to ensure the accurate tracking of the satellite / object in orbit you want to receive signals from