 The Sector General series defined the subgenre of multi @-@ species medical stories , although L. Ron Hubbard 's Ole Doc Methuselah stories and Murray Leinster 's Med Service stories , neither of which were highly regarded , had explored some similar themes . Sector General was " the first explicitly pacifist space opera " series , while much of contemporary space opera from the USA was notably military . Mike Resnick described the series ' characters as " the most memorable crew of aliens ever created " . Michael Ashley commented that the setting of the television series Star Trek : Deep Space Nine is reminiscent of Sector General . The Babylon 5 television series was also set in space station with atmospheres for different species . 
