Inspect the trajectory metadata
The report shows the OEM creation time and usable start and stop. A successful download does not mean the underlying prediction was generated just now. KitForma caches the shared public file for one hour, and the source can itself be older.
Only the documented ISS EME2000/UTC single-segment format is accepted. The parser validates finite state vectors, plausible ISS units and increasing timestamps. A different satellite or coordinate frame is rejected rather than interpreted with an assumed conversion.
Stay inside the usable interval
The entire requested search must fit the supplied data. The tool does not extrapolate a track beyond the last vector. It interpolates neighboring positions and velocities with cubic Hermite, then transforms from J2000 to the observer’s local horizon.
Precession and nutation are included, but this is an observation planner rather than a precision flight-dynamics service. UTC approximates Earth-rotation time, and atmospheric refraction is not applied. The sampling and model limits remain part of the output.
Treat maneuvers and revisions as reasons to refresh
Recognized event-summary times create a fifteen-minute exclusion buffer on each side. This reduces reliance on a planned event interval, but it does not discover unannounced maneuvers or understand every possible free-text event description.
An older-than-48-hour trajectory at the requested start is flagged, and a more-than-14-day-old one is rejected. Recheck the official NASA information near your session. A printed card is a snapshot of one trajectory and cannot silently update when flight plans change.