ELI5: Stronghold Station Mission reward ranks & adaptation &

Is anyone able to explain (clearly) to me what is going on with stronghold mission reward rankings, and how on earth this relates to the “Adaptation” percentage.
Many times I’ve sent missions with over 100% adaptation, for them to come back with a reward and “Rank B” … I assume it goes Rank S > A > B - but honestly, I have no idea what any of those rankings mean (besides somehow influencing whether or not I receive a “beast heart” or similar, or how it relates whatsoever to the adaptation percentage…
Thanks.

shameless bump

Wondering this myself