A designation used by the European Space Agency for the launch and first few orbital revolutions of a spacecraft. The launch phase begins 10 hours before launch and ends 18 minutes and 25 seconds after lift-off as the satellite separates from its launch vehicle. Before a satellite goes into orbit, its on-board computer initiates an acquisition sequence of automatic operations, pointing the payload instruments to the Earth and otherwise preparing the spacecraft for orbit. The early orbit phase during the first few hours comprises operations on board and at ground stations to make the spacecraft fully operational.
Subjects: Astronomy and Astrophysics.