3 ms·

I don't think it's so much about age as it is about design. From my understanding the original NK 33 rocket engines used a unique oxygen-rich fuel turbo-pump me

I don't think it's so much about age as it is about design. From my understanding the original NK 33 rocket engines used a unique oxygen-rich fuel turbo-pump mechanism that the west considered too dangerous. Aerojet-Rocketdyne took these engines and refurbished them and therein lies the question. But I think it might be premature to ask this given they haven't told us what happened. The thing is they are very powerful engines and the price was right.

avmich 12y ago
It's not that unique - in Russian space school oxidizer-rich turbines are routine. Proton, for example, used to have - until latest years - a pretty solid track record, especially for first stage engines, and those engines use N2O4 for turbines. Considering that N2O4 is burned with some amount of (CH3)2N-NH2, making HNO3... the gas going to chamber from turbine is the nitric acid. Still engines work just fine. One of big reasons for Russians to use oxydizer-reach gas generators is that on the rocket there usually much more oxidizer - by mass - than fuel, which makes the flow through the turbine much bigger - several times. So efficiency of turbopumps goes up. That justifies the complexity of having oxidizer-rich gas flow before the chamber.