The National Science Foundation (NSF or the Foundation) was established by Congress in 1950 as an independent federal agency with a mission "e;to promote the progress of science; to advance the national health, prosperity and welfare; to secure the national defense; and for other purposes. This book discusses the opportunities and challenges for leveraging and expanding the National Science Foundation mission to continue to advance excellent research; improve STEM education and research training; increase research accessibility, accountability, and security; and accelerate research to address major societal challenges.