> in the absence of a Shuttle fleet they cannot be refuelled. Judging by the publicly-released payload specs for the DoD-operated Boeing X-37 spaceplane, it sh

> in the absence of a Shuttle fleet they cannot be refuelled. Judging by the publicly-released payload specs for the DoD-operated Boeing X-37 spaceplane, it should be able to deliver about 2000+ L of hydrazine, compressed Xenon, or other suitable fuel in a single launch. Edit: It looks like DARPA has been experimenting with "space gas station" experiments since at least 2007. https://www.space.com/3644-prototype-satellites-demonstrate-orbit-refueling.html https://www.space.com/3644-prototype-satellites-demonstrate-...