Summary: The National Aeronautics and Space Administration (NASA) uses several mechanisms to capture and disseminate lessons learned. NASA has established an agency-wide Lessons Learned Information System that managers are required to review on an ongoing basis. NASA uses training, program reviews, and periodic revisions to agency policies and guidelines to communicate lessons learned. Several NASA centers and key programs also maintain lessons learned systems that are geared toward their own staff. To improve the way it captures and shares information, NASA has developed a strategic plan, assembled a management team to coordinate knowledge management and activities at NASA's centers, and begun several information technology pilot projects. Despite the processes and procedures in place to capture and share lessons learned, there is no assurance that lessons are being applied toward future missions success. Although some lessons learning does take place, lessons are not routinely identified, collected, or shared by programs and project managers. Furthermore, there are challenges or cultural barriers to the sharing of lessons learned, such as the lack of time to capture or submit lessons and a perception of intolerance for mistakes. Although NASA's current efforts should lead to improved sharing of agency lessons and knowledge, they lack components critical to the success of knowledge management at leading organizations. Successful industry and government organizations overcome barriers by making a strong management commitment to knowledge sharing, developing a well-defined business plan for implementing knowledge management, providing incentives to encourage knowledge sharing, and building technology systems to facilitate information access. The application of these principles could help NASA to better carry out its mission.