As written in SFoS, satellites, like the now- unrated civilian patrol boats, are simply a scenario element. The only way to 'dig in' is to assign forces accordingly. This is possibly unforeseen, but probably deliberate, to force you to make choices- the only form of fixed base available is absurdly expensive to buy an unfeasible to repair.
If you want to house rule it, I'd say one for a Patrol point or 5RR- but this would be unofficial.