[stinkbeetle]

I suspect Space X has a pretty strong inkling about how to do in-space refueling. They know how to dock in orbit, they have conducted internal propellant transfer tests, they know how to offload payload from ship in orbit and keep control of it, they know how to make autonomous quick connect/disconnect couplings for propellant transfer.

They haven't strung everything together yet and it's clearly much more complex than that. Still, pieces are coming together. Why couldn't they do it a dozen times in the next year? They could have an orbital ship launched in Q3 (flight 14), test a tanker and refueling in Q4, and start fueling in the next 3 months.

That implies all the test flights go well which is a pretty long shot, but not out of the realm of possibility. Although I think it will ship reuse that will be the problem keeping them from that within a year, rather than in-orbit refueling which I suspect won't take them more than a couple of tries to get right. Reentry still looks like a beast of a problem. It's one thing to have enough of your vehicle hanging together to land it, quite another thing again to have it back in a condition you'd be able to start fueling it up again ready for the next launch and reentry to do it all again, even in days or weeks instead of hours like Space X are aiming for.