Extending the spatial and temporal boundaries of human space flight are important goals for the National Aeronautics and Space Administration (NASA), yet human space flight remains an endeavor with substantial risks. Potential hazards include exposure of the crew to space radiation, degraded crew performance related to human behavioral and other health changes, failure of life support systems, and the adverse effects of space flight on human biological systems. The Bioastronautics Critical Path Roadmap (BCPR) is designed to provide summary assessments of the importance of each risk, and the current state of science and technology with respect to minimizing them. Preliminary Considerations Regarding NASA’s Bioastronautics Critical Path Roadmap assesses the strengths and weaknesses of the content and processes of the BCPR as applied to the missions described in the President’s exploration initiative and identifies the unique challenges for accomplishing its goals and objectives.