[hoorayimhelping]

Rocket fuel typically uses either monomethylhydrazine (MMH) or unsymmetrical dimetehalhydrazine (UDMH - the more common of the two).

The link you're responding to is about tetrafluorohydrazine, which is some kind of hydrazine and fluoride. I think it's mentioned in Ignition! but I can't remember. I just remember John Clark (the author of Ignition!) being very very hesitant and even frightened of working with fluoride based fuels.

I'm not really sure how how it's tetrafluorohydrazine is relevant to the X37-B though.