Following on from someone else's suggestion (on the Steam forums) to take over one of the power stations, which just have 1 plasma turret and a nearby drone, I decided to push my luck and discovered the Epsilon Factory can also be entered without taking a hit - underwater approach, jetpack jump over the fence, and you're in the generator / constructor / core room.
You can even use their constructor before destroying the core (under the generator - may need to drill to clear some terrain) and...
Epsilon Factory - easy takeover
You can even use their constructor before destroying the core (under the generator - may need to drill to clear some terrain) and...
Epsilon Factory - easy takeover