What SGP4 predicts—and what it cannot
The Satellite Explorer uses the established satellite.js SGP4/SDP4 implementation with OMM-compatible JSON.
Mean elements
OMM records retain catalog identifiers, UTC epoch, mean motion, eccentricity, angular elements and BSTAR. CelesTrak's omitted frame defaults are Earth / TEME / UTC / SGP4.
Age and reliability
Predictions farther than three days from the epoch carry a warning. The explorer stops propagating beyond fourteen days in either direction. Drag, maneuvers and decays can invalidate predictions much earlier.
Not operational telemetry
The viewer does not receive a spacecraft's actual attitude, health, commands or exact maneuver history. Do not use it for spacecraft operations, navigation or conjunction avoidance.