Interesting that this seems like a slam-dunk argument for why reusable rockets and other improvements are practically impossible (e.g. "we might be able to achieve a microscopic improvement in efficiency or reliability, but to make any game-changing improvements is not merely expensive; it's a physical impossibility"), and wouldn't matter in any case for structural reasons (e.g. "market inelasticity (cutting launch cost in half wouldn't make much of a difference)", yet in the fifteen years since it was written launch costs have fallen to a third of what they were, continue to fall, and the number of payloads to orbit has gone up by an order of magnitude or more (so much for "market inelasticity").