[rst]

The question isn't whether they could reduce operating costs per launch vs. SpaceX. It's whether they could reduce them by enough to pay back the R&D costs, and the cost of building a much more complicated spacecraft than SpaceX's current line of boosters. (I wouldn't say that about SpaceX's planned ITS -- but that has capabilities that _Skylon_ can't touch; Skylon itself, last I checked, was never getting out of low Earth orbit, so even GTO comsats required a second stage mated to the payload in the cargo bay, a la the old Shuttle-Centaur plans.)

[WilliamDhalgren]

I don't exactly see what ITS brings to the table here, being a multi-stage rocket as anything else that puts stuff in GTO.

But anyhow yeah - the physics should favor them by practically an order of magnitude, but if they can ever survive to reap any percentage of that potential - they could just as likely just go bust at any further point in r&d, and they don't seem to have either much funding nor are they advancing particularly rapidly...

[rst]

The spacecraft portion of ITS is being designed for interplanetary travel. Skylon, as I already said, is confined to Earth orbit, with the air-breathing space-plane portion confined to LEO. (It only gets stuff to GTO or GEO with the payload-bay booster, which is a purely conventional rocket.)