Wow. This ruined some of my ambitions, but thank you for the warning and stories.
Dive in and help change things. This is a monumental challenge that requires more people that know a better way and are willing to act.
Just to not be a totally cynical asshole, I have heard NOAA is actually pretty modernized and efficient and everyone I've talked to seemed to be happy working there.
I'd also add that while the place I was at had its share of crap, the government for the most part loved our work because their previous contracting company had came in, wrote up a ton of requirements and specifications, sat around for two years and delivered nothing functional (and still got paid).