Events Timeline

The feature is present by default. Additional features can be added to the interface in order, for example, to compare different scenarios based on different events. Only one active feature is expected when solving with a physics interface. The feature allows to manage the implicit and explicit built-in events to consider during the spacecraft orbital motion.

Select the check box to enable the fast tumbling approximation at the beginning of the simulation. The approximation remains active until an event that specifies that the approximation is not longer enabled is triggered. This approximation replaces the evaluation of the radiation received by the Sun at every position by an averaged value. This option can be used if you assume that the spacecraft is tumbling sufficiently fast so that all environmental heat loads can be averaged. It saves computational time by not computing the external sources view factors.

In the list, select the feature specifying the initial pointing direction of the spacecraft.

Set thelist to the feature specifying the initial orientation of the spacecraft.

The table lists all the implicit events taken into account during the spacecraft orbit. For each event set the to any implicit available event.

Set the and the to define the spacecraft positioning when the event occurs. The positioning is repeated each time the event type is encountered.

Set the check box to control whether the fast tumbling approximation (see Initial Orientation) is active or not when the event occurs.

There are four types of predefined implicit events:

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: triggered when a user defined condition is fulfilled. This event is optional, multiple features can be added in the interface.

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: triggered when the ground station is visible from the spacecraft given the approach and elevation angles. Another event is triggered when the ground station is out-of-sight. The fast tumbling approximation is always disabled when the ground station becomes visible. When the station becomes out-of-sight the approximation is enabled or not depending on the corresponding setting in the feature. This event is optional, multiple features can be added in the interface.

Add events in the table by setting at which the event occurs and what is its corresponding and the at this time. The event is repeated every period specified in the column. Set to inf (default) if the event does not repeat. Set the check box to control whether the fast tumbling approximation (see Initial Orientation) is active or not when the event occurs.