NASA's Earth Science Data Systems (ESDS) Program requires that all software developed through research and technology awards (i.e., Research Opportunities in Earth and Space Science [ROSES] or unsolicited proposals) or other government-funded development is to be made available to the public as Open Source Software (OSS). This includes all software developed with ESDS funding used in the production of data products, as well as software developed to discover, access, analyze, visualize, and transform NASA data. This policy does not apply to commercial off-the-shelf software.

The overarching purpose of NASA’s Earth Science program is to develop a scientific understanding of Earth as a system. Scientific knowledge is most robust and actionable when derived from transparent, traceable, and reproducible methods. Reproducibility includes open access to the data and software used to arrive at results. Additionally, software that is developed for NASA should be open to the greatest extent possible in order to enable re-use across Federal agencies, reduce overall costs to the government, remove barriers to innovation, and ensure consistency through the application of uniform standards. OSS practices also facilitate collaboration between agencies and the private sector.

Peer review of science results increasingly includes open, unfettered access to underlying data, but a lack of access to the software used to produce and analyze these data limits independent confirmation. Without access to software code, reproducibility will always be suspect due to such things as coding errors, numerical inconsistencies between the platforms running the software and the ordering of subordinate processes within the code, among other factors [Ince, et al.; Hatton; Monniaux].

Natural language descriptions of algorithms, such as Algorithm Theoretical Basis Documents (ATBDs), are inadequate to address the issues above and can be translated to code in many different ways, introducing ambiguities into the review process [Gervasi & Zowghi]. As a result, many major scientific journals broadly require open access to software to ensure the integrity of the peer review process (e.g., Science), while others empower editors and referees to include code review as a prerequisite for publication (e.g., Nature).

To best meet the aforementioned goals, ESDS established this Open Source Software Policy. The scope of this policy addresses the open source delivery of software developed with ESDS funding in order to: (1) generate, discover, access, transform, and analyze NASA Earth science data and (2) ensure open peer review of findings based on these data in a manner consistent with guidance to increase collaboration with other agencies.

For more information please visit: https://www.earthdata.nasa.gov/engage/open-data-services-and-software/esds-open-source-policy