There could be a cbm that or weapon that can shoot a small fire tornado. It is about only forest fires where they occur naturally but I thought I’d remembered doing a science thing years back in school where you could make one and lo, here be how to make a small but stable firenado
https://www.stevespanglerscience.com/lab/experiments/fire-tornado/
Enough of me being off topic though, that mention of firenados got me throughly distracted 
I like the idea of something to keep a fire under the players butt, especially late game. Like FTL there needs to be a grand ending or mission to be reaching for I’d think though. Maybe even just the ocean with the goal of getting to an aircraft carrier, oil platform, etc. It could be a camp you can set up without having to build from scratch and dump ungodly amounts of resources into sounds like a decent reward/goal to me,