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Item 2 is produced by a procedure (and related quality control), to be run on working days only, and involves, e.g., filtering of Single Event Upsets (SEU), checking the behavior of the star tracker etc. The output from item 2 is (> 90%) available within 4 working days from the observation.
Item 3 is what takes time. Given the high
timing accuracy (and the consequent requirements on the system)
of XMM-Newton, the orbit determination requires microsecond
level accuracy, or in other words, orbit determination
accuracy of well below 1 km. This can only be achieved by
combining ranging measurements and a dynamic orbit model averaging
over data some 3 revolutions in the past and in the future, already
causing a delay of some 3-4 revolutions (6-8 days). As this procedure,
and its quality control, is only run on working days, the typical
delay in producing these data is around 10 calendar days.