I know ESA releases their images under a
non-commercial
use only license, but there have been attempts to try and open that
licensing up a bit more to something more akin to the standard CC-by-SA
type license.
"Standard" is overrated. It's "standard" in our little world of
free
content providers. :-)
Never forget that most people in the real world have never heard of
content "licenses".
Having been personally involved in the attempts that you mention, I can
tell you that
the issue is really complex. Any attempt at comparing ESA and NASA
completely
misses the difference between legal systems and operating environments.
trying to milk every last drop of money from
content produced by salaried employees of these governments
There's something to that but it's not the main issue in the case of ESA.