Since 1992, NASA has offered their "unclassified, unlimited" technical reports, contractor reports, NASA-authored dissertations and re-prints on the web. The subject areas include all engineering and scientific disciplines, but are heavily focused on aerospace research. NASA also makes available the reports of its predecessor agency, the National Advisory Committee for Aeronautics (NACA, 1917-1958).
The NASA sources currently available through Scirus are:
• Langley Technical Reports Server (LTRS)
• National Advisory Committee for Aeronautics Technical Reports Server (NACATRS)