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Wait. Wouldn't this be a closed system? I can't imagine they're outgassing helium?
by encoderer 12y ago
Wait. Wouldn't this be a closed system? I can't imagine they're outgassing helium?
- NickNameNick 12y agoThey aren't. The helium is cooled by the hydrogen going to the engine. You can't run the pre-cooler on the hydrogen directly, because the hydrogen infiltrates the welds (and everything else) causing hydrogen embrittlement, which will quickly tear the heat exchanger apart. http://en.wikipedia.org/wiki/Hydrogen_embrittlement http://en.wikipedia.org/wiki/Hydrogen_embrittlement