Environmental Engineering Reference
In-Depth Information
(iii)
If no cluster satisfies restriction (2), perform an angular momentum
dump and slew to the nearest remaining unobserved cluster.
(iv)
If an angular-momentum dump is needed while still observing
within a cluster, pause science and execute the dump on current
exposure completion.
3.
The secondary mission goal is to survey opportunistically ground-specified
areas of the celestial sphere for new targets. These areas have been subdi-
vided by the ground into small regions of equal size and shape.
(a)
The FSW may schedule surveys of a region if no part of the region
is further than a database-specified angle from the current pointing
direction.
(b)
No more than 2 h out of any 24-h period may be spent surveying.
(c)
If an angular-momentum dump must be performed beforehand to en-
sure that the survey can be performed without interruption, scheduling
the survey is forbidden. If a dump is needed while observing the region,
pause science and execute the dump on current exposure completion.
4.
Ground-issued realtime commands with an attached time window will be
scheduled by the FSW within that window, so as, if possible, not to in-
terfere with ongoing activities. On completion of the ongoing activity, the
realtime command is executed. If the ongoing activity will not complete
by the end of the window, the realtime command is executed by the FSW
no later than a database-specified time period prior to the expiration of
the window. If the duration of the window is zero seconds, the realtime
command is executed immediately upon receipt. If a realtime command
needs to be executed prior to the completion of the ongoing activity, the
procedure for interruption of the activity and its subsequent treatment is
specified by the onboard smart fault detection, diagnosis, isolation, and
correction (SFDDIC) Agent.
5.
Sun angle constraints may not be violated, either when slewing to a target
or when observing a target. If any target within a cluster is in violation
of this constraint, all targets within the cluster are considered to be in
violation. If any part of a region is in violation of this constraint, the
entire region is considered to be in violation.
6.
A constraint on executing science observations is that SI calibrations must
meet observation-specific accuracy requirements prior to initiation of the
observation.
Relative to the previous assumptions, the following is a characteristic ex-
ample of how FSW processing would function in performance of typical daily
activities. Having completed the last science observation in the current cluster,
the scheduling agent requests that the SFDDIC Agent validate the remain-
ing clusters relative to observing constraints. SFDDIC reports back that all
remaining clusters are valid. Scheduling then asks the data monitoring and
