The Science Alert article All Scientific Research Funded by NASA Is Available For Free is worth reading and contains several links and quotes. Here is one excerpt:
"Making our research data easier to access will greatly magnify the impact of our research," said NASA Chief Scientist Ellen Stofan. "As scientists and engineers, we work by building upon a foundation laid by others."
There are over 1,000 research articles in the database, and that number rises steadily as new NASA-funded research is released.
I'm pretty sure in its 60 year history, NASA scientists have published and NASA has funded research resulting much much more than 1,000 papers in toto.
So the headline of the Science Alert headline "...is Free" shouldn't really be present tense. Perhaps it should read "will be or is supposed to be... at some point... in the future..."
In organizations with goals, it's common, and almost absolutely necessary to add an estimated date of completion to any goal.
Question: So I'd like to ask "When will NASA PubSpace really make publicly available most of NASA funded research papers?" Does this have an estimated date of completion, or are there milestones?
This helpful NASA fact sheet: NASA’s PubSpace: A Public Portal to Peer-Reviewed Publications and Data links to the YouTube video NASA's Research Access Policy which shows a link to https://www.nasa.gov/open/researchaccess