So yes, hypergolic powered rockets are still around, but mostly they are old designs on the way out. The Proton family you mention was on the drawing board before the book was published, and is to be replaced by the kerolox powered Angara family.
Similarly, the Chinese hypergolic Long March 2/3 families are old designs in the process of being replaced by the kerolox powered Long March 5/6/7 families.
I’m not too familiar with the Long March family but that does make sense.
More random engine nerdery:
- It’s really exciting to see all of the development going into full-flow combustion metholox engines these days; BE-4 and Raptor have been incredible projects to follow.
- The Rocketdyne F-1 is still the most impressive rocket engine to me, although the RS-25 is a very close second. Watching videos of the Apollo launches and seeing those things in action is absolutely awe-inspiring.
Though there's value in keeping it simple too. Gas generator engines got us to the moon and back.
And if the goal is routine travel to Mars, I think we really need nuclear propulsion.
And yeah, F1 is really impressive. Heck, the entire Apollo program was an astounding achievement in so many ways.
Though the geek in me is disappointed that kerolox engines produce so much soot that you can't see the Mach diamonds..