horse operas and simply translated into an outer space environment, as famously parodied on the back cover of the first issue of Galaxy Science Fiction. During the late 1920s and early 1930s, when the stories were printed in science-fiction magazines, they were often referred to as "super-science epics".

Beginning in the 1960s, and widely accepted by the 1970s, the space opera was redefined, following Brian Aldiss' definition in Space Opera (1974)