Opinions expressed by Entrepreneur contributors are their own. Amazon Fire Phone, Google Glass, New Coke and Nintendo’s Virtual Boy: What do all these products have in common? They didn’t sell.

How do you close the gap between I wonder and I know? You make a prototype. A prototype is a tool that gives you a chance to investigate your ideas and explore what could, should, or would come next, ...

At the PARI Hypersonics Advanced Manufacturing Technology Center (HAMTC), from left: Nate Humbert, lead additive manufacturing engineer, GE Additive; Will DeVerter, aeronautics and astronautics ...

Radian Aerospace’s subscale prototype for its Radian One space plane sits on a runway in the United Arab Emirates. (Radian Aerospace Photo) Seattle-based Radian Aerospace has finished the first round ...

Donut Lab battery validation adds a 10-day room-temperature retention figure of 97.7%, while energy density and weight data remain absent.