[mattkrause]

If you have enough equipment, you can set up a relay where tankers themselves get refueled by other tankers. This can dramatically extend the range of a small number of aircraft, though the logistics (and expense) gets out of hand quickly.

The British did this during the Falklands War in 1982. In Operation Black Buck, a bomber from Ascension Island (near the equator), attacked Port Stanley Airport (~52°S, about 12000 km away). To do so, the bomber was refueled 7 times on the way out (and once on the return), while a fleet of tankers refueled each other 9 more times. Wikipedia has a diagram showing how this worked: https://en.wikipedia.org/wiki/Operation_Black_Buck#/media/Fi...

[gwern]

Is that equivalent to the 'rocket equation', where each tanker is analogous to another stage on the rocket? (You spend increasing amounts of fuel to get the fuel out to where it needs to be transferred in to be then burned.)

[mattkrause]

Seems very similar to me, though the constraints are a bit different: you want the tankers back, presumably, but you also don't have to move all of it together