Also in 1977 Analog, the bastion of hard-core sf (strict technological extrapolations from scientific theory), published an all-women's issue. Its cover story, ''Eyes of Amber'' by Joan Vinge, promptly won a Hugo. The Analog issue was almost revolutionary. Most women had previously felt they couldn't write hard-core sf because they were generally not - unlike earlier Analog authors - scientists and engineers. A classic example of the type of story that appeared in Analog and other hard-core magazines is Tom Godwin's ''The Cold Equations'' (1954). In it, inexorable ratios of mass and velocity to fuel - the ''cold equations'' of the title - force a pilot to choose between saving a girl stowaway or rescuing a plague-stricken colony. Out the airlock goes the girl. During what Ursula Le Guin has called the ''baboon patriarchy'' of the 40's and 50's, women characters in sf generally got about the same treatment. When they weren't being lectured by lantern-jawed scientists, they were being rescued by lantern-jawed space captains from lantern-mandibled aliens with eugenics on their nether brainstems.

Many women tended to break into the field by means of categories other than hard-core sf: ''soft-core,'' which draws upon the social sciences, ''sword and sorcery'' and ''high fantasy.'' Traditional sword-and-sorcery is a genre in which lightly-clad women shrieked and were abducted by heroes heavy on testosterone and light on brains. In high fantasy, ladies embroidered, cast spells and wore medieval garb while their lords battled dragons, orcs and archaic diction.

THE women infiltrating these genres transformed them. Vonda McIntyre combined her training in genetics and sociology in her soft-core bildungsroman about a female healer in a post-nuclear holocaust world, the sf best seller ''Dreamsnake'' (1978). Probably one of the most extraordinary examples of soft-core sf is Ursula Le Guin's ''The Left Hand of Darkness'' (1969), which reflects the author's formidable background in anthropology as well as her overriding ethical and artistic concerns. In ''Left Hand'' Le Guin constructs a glacial world as painstakingly as Frank Herbert created the desert ecology of ''Dune.'' But unlike ''Dune,'' Le Guin's world of Winter has never known battling, of either armies or the sexes. There are two reasons for this: the logistics of warring on ice and the fact that the planet's inhabitants are hermaphrodites. When an ambassador from a planet accustomed to male dominance meets these people - Le Guin's variation on the time-honored First Contact convention of pulp fiction -what happens? Certainly not the conversion of Winter's people to the ways of the earthlings.

Writers like Andre Norton and Marion Zimmer Bradley, both nonscientists, worked the same metamorphosis on sword-and-sorcery and on fantasy. Bradley may have followed C.L. Moore in creating Amazons, but she raises her book ''The Shattered Chain'' above the level of heroic fantasy by having her characters explicitly debate the varieties of feminist theory, discussing among other things the merits of celibacy, lesbianism and conventional marriage. In ''Witch World,'' Andre Norton pioneered serious treatment of matriarchy in fantasy, but became somewhat of a disappointment to feminists for her insistence that matriarchies can be just as static and repressive as maledominated cultures.

PERHAPS the most versatile talent of the 70's and 80's is the classics teacher C.J. Cherryh. Though she has written voluminously since age 10, publishers' rejections made her hide her manuscripts in a closet until a tentative query finally brought her the attention of the dean of science fiction editors, Donald A. Wollheim of DAW Books. Since the 1976 publication of ''Gate of Ivrel,'' Cherryh, now 40, has been happily blending sf genres and turning the conventions of the field upside down. Her first novel inverts oldstyle sword-and-sorcery by making the warrior-hero a female and the bond-servant a male. In her second novel, ''Brothers of Earth,'' the human who makes contact with aliens, in this case a people practicing the family values of ancient Rome, tries to adopt as much of their way of life as possible. In fact, Cherryh's fiction rejects totally the pulp-sf notion that when human meets alien, the alien is either killed or converted to human ways. This is especially true in ''The Fated Sun,'' her recent trilogy about alien mercenaries.