When I load up the game, memory usage sits around 2100 MB. When I go into the first outpost, it increases to about 2300 MB. While playing that outpost, memory slowly creeps up. After the fifth/sixth attempt, it was over 2400 MB. Every attempt saw my memory usage go up more and more.
When I abandon the raid and return to my base, the usage drops back to ~2100 MB.
There is some sort of leak occuring or lack of garbage collection that occurs you're raiding an outpost that continues to accrue the more attempts you make.