The Tau Zero Foundation , or Tau Zero Foundation for Interstellar Spaceflight , is a spinoff of the NASA Breakthrough Propulsion Physics Project ( BPP ), a research project that ran from 1996 through 2002. NASA established the program to study proposals for revolutionary methods of spacecraft propulsion that would require breakthroughs in physics before they could be realized. During its six years of funding, the program was supported with a total investment of US $1.2 million.
NASA Breakthrough Propulsion Physics
The NASA Breakthrough Propulsion Physics Program was a 1996–2002 research program that aimed to find ways to achieve interstellar spaceflight on realistic mass and energy timescales. The program examined propellantless propulsion, hyperfast travel, and breakthrough propulsion. At the end of the project, four research avenues were identified as opportunities for continued research.
Frontiers of Propulsion Science
After conclusion of NASA funding into the program, principal investigator Marc Millis and physicist Eric Davis documented the results in the book Frontiers of Propulsion Science , published in February 2009 by the American Institute for Aeronautics and Astronautics ( AIAA). Its “Chapter 3: Prerequisites for Space Drive Science” provides a deeper explanation of several proposed spacecraft propulsion methods.  
Following the close of the program in
2002, Millis joined several project members to establish the Tau Zero Foundation , a nonprofit organization advocating research into interstellar travel. The name stems from the science fiction novel Tau Zero , which chronicles an interstellar voyage and the lives of its participants. Millis retired from NASA on February 3, 2010, continuing interstellar research at Tau Zero.
Notable leadership includes board directors Walter De Brouwer  , cofounder of Starlab ; Starlab alumnus and NASA-trained commercial astronaut , quantum technologist Christopher Altman ;  founder of XCOR Aerospace, Jeff Greason ,  joined as chairman of the board in October 2017. 
In April 2017, NASA awarded Tau Zero a $500,000 grant for the study of breakthrough propulsion programs in a funding proposal entitled Interstellar Propulsion Review.  A summary of work to date was given by Millis in a talk at the 2017 Tennessee Valley Interstellar Workshop, Breakthrough Propulsion Study . 
The foundation has been covered in press and publications including The New York Times ,  Scientific American ,  Discover Magazine,  ABC News,  NBC News,  Fortune,  Forbes,   The Space Show,  Phys.org,  Centauri Dreams,  Seeker.com,  Popular Science,  Space.com,  Jezebel.com, BigThink, Futurism,  Next Big Future,  h+ Magazine,  Wired,  The Guardian,  China Daily,  Slate  and Spiegel.