I'm on the road again, putting stuff on a boat to go test it and I'm looking around and other than the geeks, everybody else has gray or white hair (if they have any hair left)...RTWT.
Ages are 68, 67, 66, 66, 63, 61, 59, 58, 58, 56, 53 and 51, or an average of 60+ years; and all of the scientists were over 60 too (one is 79 years young). Two guys were lured back out of retirement to come work on this stuff. We were in at 0630 every morning, worked until about 1900, and did it again and again till we were done. And some of the stuff was 'designed' on the spot to get things done...
But a problem (or at least my perception), is there are NO younger people in training for any of our jobs. I literally went around to the various organizations represented and asked! The consensus was when we all retire (I think ALL of us will be gone within 5-6 years), there will literally be no one with the capability to build/integrate/assemble/deploy/retrieve systems like this; much less anything larger.
I'm an engineer, working for a not-small engineering company. In my department we have several engineers past retirement age working part-time to supplement their incomes (and because they have the experience, knowledge and judgment that younger engineers lack). Read what Old NFO has to say about the younger members of his "team." This is not atypical in my experience. And it's a for-real problem.