"Liquid/liquid engines, by any measure, are orders of magnitude more stable."
What do you mean by stable?
A reason to go with hybrids, at least on paper, is that they are mechanically simple but throttlable, hopefully combining the simplicity of a solid booster with the ability to throttle and shutdown of a liquid.
Of course, much of that also applies to blowdown liquid systems, and I personally find a blowdown methane/lox system particularly compelling. I figure Virgin wanted to avoid cryogens, though.
I think Paul McCartney was about 23 years old when the engines powering that Antares launch vehicle were fabricated in Russia in their race against the Americans to the moon. An antique liquid/liquid vs an inadequately qualified hybrid: no winners.
I'm not sure what constitutes adequate qualification, though. Both engines were ground tested at least some. And in Virgin's case, this flight was one of tests.
http://en.wikipedia.org/wiki/NK-33 says the AJ-26 engines are from the 1960s and 1970s.
This you believe so strongly because a news story stated it?
Wait for the accident report. It will say "rubber".
Problems like these are almost always the result of management pushing things faster than the engineering progress warrants.
"Problems like these are almost always the result of management pushing things faster than the engineering progress warrants."
Coincidentally, we were talking about such an instance today at work, the Conestoga 1620. As relayed to me, the "low frequency noise" mentioned in the wikipedia post was a low frequency structural mode that was missed because management didn't want to pay for a high enough fidelity finite element analysis.
“This was a new fuel formulation that had been proven and tested on the ground many times,” Mickey said in a press conference.
http://spaceflightnow.com/2014/10/31/virgin-galactics-spaces...
I have heard of one long duration test on the plastic fuel reported by the "Virgin watchers" in Mojave, so unless they are doing long duration tests somewhere else it doesn't seem like much. Rocket engine testing is extremely noisy so long duration tests are quite noticeable.
1. They didn't stay with rubber/nitrous.
2. Like the sort used on Antares?
"Seeing only the first paragraph, I already know that some rubber in the hybrid engine detached blocking the nozzle and causing the whole engine to explode."
But what you know is wrong, they weren't using rubber.
I think a good case can be made that they didn't do enough ground testing, but your post mixing disdain and falsity doesn't advance that case.