COLORADO SPRINGS—Looking to start space-tourism flights in 2018 that he predicts will open the floodgates for a new breed of entrepreneurs, Amazon.com Inc. CEO Jeff Bezos said in some years he has personally invested up to $1 billion to further those goals.

Flanked by a New Shepard rocket featuring the telltale scorch marks of multiple flights, Mr. Bezos appeared before a gaggle of reporters during a conference here Wednesday to lay out his vision for Blue Origin LLC, the company he founded more than a decade ago to lower...