every time this space-x stuff comes up, I always take a moment to remind people of Reaction Engines and - Skylon [http://www.reactionengines.co.uk/space_skylon.

every time this space-x stuff comes up, I always take a moment to remind people of Reaction Engines and - Skylon [http://www.reactionengines.co.uk/space_skylon.html http://www.reactionengines.co.uk/space_skylon.html] I realise there's practical differences in terms of the current rate of progress between Space-X and Reaction Engines, but in the long term (and making the huge assumption that they'll get Skylon built), I think Reaction Engines has the better plan.