That can be done easily using a fleet with Cycle Orders turned on.
Yes and no, because that could be achieved with a series of order delays but you need to time it properly or if the order triggers at the wrong moment you will end up with the error: this order will result in an endless loop and has been cancelled
it always require some manual intervention.
I think you can use order delay to time your runs as I assume you are going A to B where both are Stationary (if either A or B are moving this will be impossible). So you can send the cycle moving from colony pick up fuel and then go to station, set something like 2 or 3 days delay to refuel and it will run as long as when the order triggers the tanker it's there. You need to start the chain with the supply ships on the station otherwise you will not be able to set the refill orders from the station.
But you are right: you will loose the sync sooner or later and some manual intervention will still be required, but not for every single run as you could time 3 or 4 runs at the time. and considering you don't want to always refill you may be fine for 5 or even 10 years. Still a pain of course.
PLEASE NOTE: I haven't tested this method myself yet as I have little use for stations, but it should be feasible following the logic behind the orders unless you will receive the error as soon as the fleet leaves the station? Maybe you can try or I may give it a spin later on. Not much time to play this week.
