National Aeronautics and Space Administration (NASA) Headquarters is releasing an Appendix to the current Space Technology Research, Development, Demonstration, and Infusion 2015 (REDDI) NASA Research Announcement (NRA) for initial studies of visionary aerospace concepts. NNH15ZOA001N, entitled NASA Innovative Advanced Concepts: Phase I Studies, will be available as of October 10th, 2014 by opening the NASA Research Opportunities homepage at http://nspires.nasaprs.com/ and then linking through the menu listings "Solicitations" to "Open Solicitations." This NRA Appendix will solicit multiple studies, each of which will investigate an architecture, mission, or system concept with the potential to enable a great leap in space or aeronautics. Aerospace architecture, mission, or system concepts proposed for NIAC Phase I study must be exciting, unexplored, far-term, and credible. Proposals for narrow technology or subsystem development, or incremental or near-term advancement, are explicitly out of scope for this program. Finally, while NIAC encourages daring vision and accepts the accompanying risk, proposals must be technically credible and plausibly implementable. NIAC is part of the Space Technology Mission Directorate. The 2015 NIAC Phase I solicitation will be a two-step process. Step A will be a 3-page white paper plus summary chart. Proposals shall be submitted electronically, and all Step A proposers shall use the NASA Solicitation and Proposal Integrated Review and Evaluation System (NSPIRES), accessible at http://nspires.nasaprs.com , or for Step A may also use Grants.gov. Step B full proposals will be eligible only if invited after review of a Step A submission. Step B proposals shall be submitted electronically through NSPIRES only. This solicitation will be an open announcement; anyone is welcome to respond. Affiliation with any educational institution, commercial or not-for-profit organization, research laboratory, government agency, or NASA Center (including the Jet Propulsion Laboratory) is permitted. Individuals may submit, as long as they meet the registration requirements for NSPIRES. Every organization that intends to submit a proposal in response to this NRA must be registered with NSPIRES, and such registration must identify the authorized organizational representative(s) who will submit the electronic proposal. Each electronic proposal system places requirements on the registration of principal investigators and other participants (e.g. co-investigators). Potential proposers and proposing organizations are urged to access the electronic proposal system(s) well in advance of the proposal due date(s) to familiarize themselves with its structure and enter the requested information. Specific propo sal submission deadline dates, evaluation criteria, and submission information will be identified in the NRA. Step A White Papers will be due on or before Wednesday, November 12th, 2014; Step B full Proposals will be due on or before Wednesday, January 21st , 2015. 12-16 NIAC Phase I awards are anticipated, but the final number of awards will depend on the quality of proposals and availability of appropriated funds. Comments and questions may be addressed by e-mail to NIAC Program representatives at hq-niac@mail.nasa.gov . Responses to inquiries will be answered by e-mail and also included in the Frequently Asked Questions (FAQ) document located on the NSPIRES page associated with the solicitation; anonymity of persons/institutions who submit questions will be preserved.