Legacy
After funding for research ended, the Project's founder and manager, Marc G. Millis, was supported by NASA to complete the documentation of results. The culmination of that work is the book, Frontiers of Propulsion Science, which was published in February 2009, by the American Institute for Aeronautics and Astronautics (AIAA). Chapter 3 (Prerequisites for Space Drive Science) provides refinements and deeper explanation of the following hypothetical "space drive" propulsion methods: diametric drive, pitch drive, bias drive, disjunction drive, and three variations of differential sails.
After the BPP was canceled in 2002, some former members, including manager Marc G. Millis, founded the Tau Zero Foundation (named after the novel of the same name), an organization that advocates research into interstellar travel. The new organization is not affiliated with NASA. Millis retired from NASA on February 3, 2010, and continues to pursue similar research via Tau Zero.
Read more about this topic: Breakthrough Propulsion Physics Program