Possible incorrect drag implementation in BoxAndSolarArraySpacecraft

Orekit usage
1

Hi :slight_smile:

I’ve been in the process of upgrading our system from version 9.3 to version 12.0.1, and think I may have found a bug in the new BoxAndSolarArraySpacecraft implementation of the dragAcceleration function. I believe the drag factor is being applied twice when calculating the accelerations, the first on line 182, and the second on line 196.

Could I get a second pair of eyes to take a look?

Thanks in advance!

Jake

2

No the two drag factors are different ones. The one used at line 182 is a global multiplicative factor that can be estimated, but which is 1.0 by default. It corresponds to the first parameter driver set up at lines 104/105 with name DragSensitive.GLOBAL_DRAG_FACTOR. The one used at line 196 is the individual factor for the current panel.

3

Thanks Luc for the explanation - I had missed the series of global multiplicative factors for the various facet coefficients that had been added since the 9.3 release. Consider it not a bug then!