This is really quite a big deal. A tremendous amount of modern research ends up being sold to journals which require unreasonable payments to access it and only pay the original authors a pittance. It’s nice to see an agency like NASA deliberately widebanding its findings.
Direct link to the NASA page on PubMed: http://www.ncbi.nlm.nih.gov/pmc/funder/nasa/
For yet more freely available science, check out the Public Library of Science: https://www.plos.org/