For kids of the ’60s, it was a thrilling weekly ride and for adults revisiting it later, it became a time capsule of an era when television dared to mix earnest family drama with outlandish spectacle.

LOS ANGELES — June Lockhart, who became a mother figure for a generation of television viewers whether at home in “Lassie” or up in the stratosphere in “Lost In Space,” has died. She was 100. Lockhart ...