facetSRPDynamicEffector does not account for eclipse shadow

[themouli]

Describe the bug
The facetSRPDynamicEffector module applies full solar radiation pressure regardless of whether the spacecraft is in Earth's shadow. There is no sunEclipseInMsg input on this module, so eclipse conditions are not considered in the force/toque calculation.

• SRP force and torque are overestimated by the eclipse fraction of each orbit (~30-35% for typical LEO Sun-synchronous orbits).

Additional context

• Add a sunEclipseInMsg input to FacetSRPDynamicEffector
• Read the eclipse shadow factor in computeForceTorque()
• Scale the SRP pressure by the illumination factor (0.0 = full shadow, 1.0 = full sunlight)

[schaubh]

Howdy @themouli , thanks for contributing this enhancement. We recently came across this limitation as well.

Note that we changed the name shadowFactor to illuminationFactor and deprecated shadowFactor. The new name makes more sense when a value of 1 means we are fully illuminated, and a value of 0 means we are fully in shadow (not illuminated).

[themouli]

Thanks for the feedback @schaubh. Updated the code to use illuminationFactor instead of shadowFactor.

[schaubh]

Also, please be sure to squash your fixes with the earlier commit to yield a clean commit history. The release notes snippet can be its own commit, but the other commits should be squashed with the earlier commits, thanks.