At various times, Stephen Fleming has been paid to be an optical physicist, laser fabricator, software developer, field engineer, product manager, corporate trainer, marketing executive, salesman, general manager, entrepreneur, author, venture capitalist, board member, investment banker, consultant, angel investor, public speaker, adjunct university faculty, commercial landlord, academic bureaucrat, and economic developer. Stephen is active in the "alternative space" industry; he is an investor in over a dozen private aerospace companies and is a founding member of the Space Angels Network. In 2017, he founded the Arizona Space Business Roundtable in Tucson.