Tiptree/Sheldon was an eclectic writer who worked in a variety of styles and subgenres, often combining the technological focus and hard-edged style of "hard" science fiction with the sociological and psychological concerns of "soft" SF, along with some of the stylistic experimentation of the New Wave movement.
After writing several stories in more conventional modes, she produced her first work to draw widespread acclaim, "The Last Flight of Doctor Ain", in 1969.