Originally Posted by
MostlyHarmless
The space industry seems to have an awful lot of problems with valves, cryogenic or otherwise.
A big part of the problem is that the launch rate is so pathetically low - right now ~ one launch every two years. During the 1960's moon race, they were launching every 2-3 months, and even after Apollo 11 successfully landed on the moon, the rate was still 2-3/year.
When you're doing the same job every few months, you learn and remember what can go wrong (and what to do about it when it does go wrong). With two years between launches, people forget or leave for other jobs, and every flight becomes basically a prototype 'first flight'.
And the SLS is so ungodly expensive, that's not going to change because they can't afford to do more frequent launches.
Space X is launching several times per month - and they're not having those issues.