Author Topic: SpaceX early problems with Merlin (Read 27672 times)

Danderman · « **on:** 03/12/2024 03:40 pm »

According to Eric Bergen's book "Liftoff", there was a point in the development of Merlin where Elon was at the point of despair.

I happened to know about it at the time, because Elon was looking around for an alternative, and I ended up being a stuckee for the assignment of finding a decent replacement. At the time, the NK-33 was the fan favorite, with many proposed designs incorporating NK-33. But Aerojet had grabbed all of the existing supply from the Russian manufacturer, and Aerojet's price was rather high.

Fortunately, I knew of an alternative supply, and was sent to Russia to investigate.

I ended up at SNTK in Samara, the design bureau for the engine. For political reasons, SNTK had been barred from development of new rocket engines for decades. The question was whether they had any NK-33s left, and could they support continued use.

After an initial consumption of mass amounts of vodka, I was shown their considerable supply of NK-33s in their pilot production facility, which I duly reported. But, by then, the Merlin problems had been resolved.

I suspect that the NK-33s I saw were subsequently used in the Soyuz-V launcher.

The Aerojet engines came to a bad end, I suspect, because they came from the manufacturer, not the design bureau, and so there was not so much technical insight into the engine. Just a guess.

AS-503 · « **Reply #1 on:** 03/12/2024 03:46 pm »

Thanks for the post!
My understanding was that the specialized coatings in the oxygen rich side of the plumbing had suffered ill-effects from long term non-environmentally controlled storage.

Danderman · « **Reply #2 on:** 03/20/2024 05:28 am »

Quote from: AS-503 on 03/12/2024 03:46 pm

Thanks for the post!
My understanding was that the specialized coatings in the oxygen rich side of the plumbing had suffered ill-effects from long term non-environmentally controlled storage.

The NK-33s from the manufacturer had been stored in a shed, whereas the NK-33s produced by the design bureau were stored inside their facility.

lrk · « **Reply #3 on:** 11/16/2024 04:48 am »

There was also evidence of a machining error on the turbopump bearings, from when they were originally manufactured. After the accident, they managed to recover much of the failed engine. The stationary part of the bearing was intact, and was found to be slightly out of tolerance. This matched another engine that had failed on the test stand, and at least one other unflown engine in their inventory.