Hydrazine filling of the first tank in the attitude control system, on Wednesday 14 October at the Guiana Space Centre, took longer than expected, although the filling operation itself was completed.
In view of the pre-launch operations still to be carried out, the Ariane 503 launch has therefore been put back 24 hours. The next key event, the Launch Readiness Review, will take place on 16 October and will clear the way for rollout to the launch zone, now planned for Tuesday 20 October.
In view of the above, the launch is now planned for:
Wednesday 21 October: launch window 13:00 to 14:30 local time or 16:00 to 17:30 UT; 18:00 to 19:30 CET.
Ariane-5 is an ESA programme for which ESA has delegated management responsibility to CNES.
Flight 503, conducted under ESA responsibility, will be the last of the Ariane-5 qualification flights. The launcher used will be the first production-series unit ordered by Arianespace from European industry.
Launch operations are managed by Arianespace at the ELA-3 launch site at the Guiana Space Centre, Europe's space port.