If you're launching the fuel for the purpose of extending the range of a probe, well, of course you'll put it in the right place. There's no point of conceivin

If you're launching the fuel for the purpose of extending the range of a probe, well, of course you'll put it in the right place. There's no point of conceiving of a world where we can afford to launch fuel but still have to treat every single launch as exceedingly precious and expensive such that we can only afford to set up One Fuel Depot in space, the way we have One Space Station. Either this gets cheap enough that SpaceX basically has a "launch + more fuel launch(es)" as a standard package or it never happens at all, there isn't much in between.