Ephemeris Data

We update the data for each satellite on a weekly basis, usually on Thursday and Friday. The start dates are Saturday and Sunday, respectively, and are valid for a period of seven days from epoch.

We provide additional data when station-keeping or relocation maneuvers are scheduled - typically one to three messages per month. Maneuver files may be issued any day of the week, and become effective at the time of the maneuver. They remain effective until superseded by another maneuver update file or by the next set of routine weekly data.