4.6.2 Science Instrument OV Phase Activities

The schedule of activities is constrained by when it is safe to perform some tasks and by time order dependencies between tasks. Many of the verification tasks require the instruments to image the sky, which in turn requires the telescope sunshade door to be open. The sunshade door cannot be opened until the ACIS camera housing door is opened and the forward contamination monitor sources are measured. The ACIS door cannot be opened until the OBA has sufficiently out-gassed and vented overboard. Thus the opening of the ACIS door provides a natural breakpoint in the schedule of activities. In what follows we will refer to the period before the opening of the ACIS door as Period 1 and that after the door is opened as Period 2.