ISS Viewing Planner: Local Pass Times, Directions & Observation Cards

No. These are predicted candidate intervals based on the supplied trajectory and your rules. Clouds, haze, an obstructed horizon, station brightness, revised flight plans and timing error can affect visibility. Recheck NASA information and local conditions before observing.

The planner includes only the part above your minimum elevation while your Sun is below the selected limit and the station is fully sunlit in the geometric shadow model. It excludes penumbra. A candidate can begin or end because one of these conditions changes, even though the station remains above the horizon.

Only a single-segment NASA ISS OEM 2.0 for object 1998-067-A, Earth center, EME2000 frame and UTC time is accepted. Position is kilometers and velocity km/s. Cubic Hermite interpolation uses both; J2000 vectors are transformed to local horizontal coordinates with precession and nutation.

The complete search must fit the usable OEM interval and extrapolation is disabled. A trajectory older than 48 hours at the requested start is flagged; more than 14 days is rejected. Recognized event-summary times exclude 15 minutes on each side. This cannot detect unannounced or differently described maneuvers.

It uses the available MET Norway cloud fraction at the candidate’s sampled peak time. Unknown or unavailable weather does not pass. It does not certify clear sky for the entire pass. Rounded coordinates are sent through a caching gateway; the forecast source and times appear in the evidence.

Yes. Printable HTML cards include directions, approximate times and spaces for observations. SVG sky tracks and CSV candidate lists work offline after download. The JSON preserves trajectory metadata and calculation choices. A saved plan does not update itself, so refresh it near the observation date.