John Hendricks started Discovery Channel in 1982, after watching HBO succeed in the 1970s. He made a fortune and left as chairman of parent company Discovery Communications last spring to pursue his new venture.

On Wednesday, CuriosityStream launched with about 600 series, feature-length documentaries and 20-minute-or-shorter clips on science, technology and history.  Access costs $2.99 a month for standard-definition picture quality and $5.99 a month for high definition. The first month is free.

CuriosityStream is expected to feature a mix of content acquired from BBC, NHK and other producers as well as original programming. Aimed at the "curious" population, the programming should be understandable, Hendricks says, to everyone from 13-year-olds who enjoy building soda-bottle rockets to retirees looking for deep commentary on the latest scientific breakthroughs.