so how do they intend to create the hydrogen fuel?
By burning more fossil fuel?
That'll hardly leave a carbon footprint...
From
http://www.reactionengines.co.uk/lapcat.html
Analysis of the Development, Production and Operating costs suggests that the average ticket price would be comparable to an existing Business class ticket... This estimate assumes hydrogen fuel derived from water electrolysis whereas the ticket price would roughly halve if the hydrogen is produced by steam reforming.