NASA published the following announcement, effectivley giving free public access to NASA research papers:
NASA is using PMC to permanently preserve and provide easy public access to the peer-reviewed papers resulting from NASA-funded research. Beginning with research funded in 2016, all NASA-funded authors and co-authors (both civil servant and non-civil servant) will be required to deposit copies of their peer-reviewed scientific publications and associated data into NASA’s publication repository called NASA PubSpace. This exlcudes patents, publications that contain material governed by personal privacy, export control, proprietary restrictions, or national security law or regulations. NASA PubSpace is part of PubMed Central (PMC) which is managed by the NIH.
You can now search NASA related articles archived in PMC at NASA PubSpace. PubSpace will be fully functional Fall of 2016.
Already over 800 recent research articles, published within 2016, have been uploaded in PDF format to the site, which uses the infrastructure of the US National Library of Medicine, National Institutes of Health.