Ariane 501: transfer to course correction
The alignment calculations are complex:
- need about 45 minutes to initiate
- results are transferred to the course correction subsystem about 10 seconds before liftoff
The alignment calculations would have to be re-initiated if the countdown was suspended within 10 seconds of liftoff
- possibility to miss a launch window
- possibility to lose the cost of a launch
Work around:
- the alignment calculations were stopped only 30 seconds after liftoff
- possibility to transfer calculations to ground computer