The series premiered in
1964. Stopped in 1969 after 18 issues.
The series is based on a straight action science
fiction theme and has no starring characters. The stories
usually have the same main theme; an unprepared Earth is
attacked by ferocious aliens from outer space, and scientists
and soldiers struggle to defeat them.
The series is a spinoff from a TV
series that ran from 1963 to 1965.