Startup Gauntlet introduces a focused path to entrepreneurship called Customer Discovery. This six-week long program covers the process of identifying the core of a startup business. Anyone may enter the class, with or without a concept for a business, and learn how to make and test assumptions about a potential business, by performing in-depth Customer Discovery. The result will be a business model based not on an entrepreneur's guesses, but on facts learned directly from potential customers. Sponsored by a grant from the National Science Foundation, since May 2012 Startup Gauntlet has been taught to more than 120 teams in eight cohorts. (June 2013)