Comments on: Problems discovered in new Japanese H3 rocket engine https://behindtheblack.com/behind-the-black/points-of-information/problems-discovered-in-new-japanese-h3-rocket-engine/ Wed, 02 Dec 2020 00:30:36 +0000 hourly 1 https://wordpress.org/?v=6.9.4 By: Dick Eagleson https://behindtheblack.com/behind-the-black/points-of-information/problems-discovered-in-new-japanese-h3-rocket-engine/#comment-1095777 Sat, 28 Nov 2020 20:46:48 +0000 https://behindtheblack.com/?p=71165#comment-1095777 Given that turbopumps and combustion chambers are the most highly-stressed components of rocket engines, it is hardly surprising that they account for an outsized fraction of the total problems arising in development of new engines. Turbopump and combustion chamber problems were apparently at the root of early Long March 5 failures in China. The same has apparently been true of Blue Orgin’s BE-4 engine. Now such problems are biting the Japanese.

Even the most successful and fastest-moving rocket company on Earth, SpaceX, has suffered similar difficulties in the process of developing and improving its Merlin and Raptor powerplants. Turbopump fatigue cracking, in particular, was an issue with later versions of the Merlin 1-D as its power was increased. Early versions of Raptor also suffered such problems. Given both the extraordinary performance and modest size of both engines, it would have been very odd for such not to have been the case. In both the Merlin and Raptor cases, “the fitful demons chained within their engines,” as Robert Heinlein once put it, have been incrementally tamed by increasing sophistication and subtlety in design, metallurgy and control systems.

As with SpaceX, Blue Origin and the Chinese, the Japanese will find solutions for their current problems too.

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