[jabl]

> I'm not sure the switch to IRFNA/NTO is for safety reasons. There is simplicity involved - you don't need catalyst with them.

Yeah, good point, that's certainly an advantage.

> Here are some comments on safety.

> https://yarchive.net/space/rocket/fuels/peroxide.html

Coincidentally(?) those comments stop in the year 2000, when the Kursk put a dent in HTP enthusiasm. For a while at least.

Not that I have any good solution either. Seems all high performance liquid rocket fuels have some nasty downsides.

For small scale applications N2O + some light hydrocarbon like propane or ethane could be interesting. But that seems to be quite immature, so could be some showstoppers ahead in that path.