Let’s be fair about Russian engines

29 12 2014

The Motley Fool just posted an article about Orbital Sciences electing to replace the Soviet-designed and Soviet-built NK-33 engine on its Antares rocket with the Russian-built RD-181, an offshoot of the RD-180 engine currently in use on the Atlas V. The article then went on to speculate about this decision ultimately being a win for SpaceX, an American company that designs and builds its own engines for for its own rockets. I scrolled down to the comments section, which was my mistake, to see lots of people who clearly know nothing of rockets or aerospace engineering, but know they don’t like Russia, pissing on the RD-181.

In any engineering field, knee-jerk reactions are less tolerable than in other, less rigorous fields. When selecting an engine for a rocket, you have to look facts and statistics squarely in the eye and calmly make a logical, justifiable choice. The NK-33, RD-180, and RD-181 are all proven, powerful engines that meet the requirements for their rockets. The only American engine to outperform all Russian/Soviet engines in terms of thrust-to-weight ratio is the Merlin 1D, currently in service on the Falcon 9.

Whether Orbital thought they could get a better price on the RD-181 or SpaceX was not interested in selling its engines, I have no idea. The NK-33 is the second-most powerful LOx/kerosene engine in terms of TWR and the RD-181 is the third.

When the modified NK-33s (later renamed AJ-26) were installed on the Antares rocket, both engines had been taken apart, rebuilt, test, fired, and tested again. These were not some chunks of rust that Orbital got for a deal on the Russian black market. These were well engineered, tested, and vetted engines. Unfortunately, you cannot remove every bit of risk from a launch.

I don’t like what Russia has been doing to its neighbors, Ukraine in particular. I don’t like that they make so much money off oil and gas any more than we use lots of oil and gas. I think there were managerial oversights during the Shuttle-Mir program. I, like most Americans, have reasons to not completely trust Russia. However, feelings mean nothing when you are staring at specs and data and trying to make an engineering decision.

If you are an American and you want us to have better, more powerful, more efficient, and more reliable engines than the Russians, go out and build them. Otherwise, shut up about it and accept that Orbital made the best decisions they could and that’s all we can expect of anyone.