Ultra-imagination and space chases; Ballad of the Stars, by Genrikh Altov and Valentina Zhuravlyova. Translated by Roger DeGaris. New York: Macmillan. 300 pp. $15.75.; Foundation's Edge, by Isaac Asimov. New York: Doubleday. 384 pp. $14.95.; The Fall of the Shell, by Paul O. Williams. New York: Ballantine/Del Rey. 214 pp. $2.50 (paperback).

While readers most often look to science fiction to provide a sense of wonder derived from scientific advances or otherworldly situations, three recent works prove that this genre may also offer a sense of wonder about the complexities of the human condition, or the indomitability of the human spirit.

''Ballad of the Stars,'' an anthology of stories by Soviet science fiction writers Genrikh Altov and Valentina Zhuravlyova, demonstrates the authors' profound insights into human character as challenged by vigorously different situations. This is superior science fiction, indeed, in which scientific possibilities are blended with sensitive observation of human behavior.

Altov's contemplative lead story, for instance, portrays a scientist who must weigh the sacrifice of his life's work against certain loss of the lives of three scientists trapped underground during a venture of scientific exploration. Evocative description of small details combines with an effectively understated conclusion to give this story a Gorkyesque impact, as the isolated scientist finds himself experiencing anew an identification with and a concern for the whole of humanity.

Zhuravlyova's contributions include three stories based on the experiences of Kira Vladimirovna Safrai, a psychologist who is able to guide talented scientists in the development of ''ultra-imagination.'' ''Snow Bridge Over the Abyss'' recounts Kira's accidental discovery of ultra-imaginative ability in a young mathematics student called Nastya. Charged with tutoring Nastya to ready her for an examination, Kira finds that by developing the student's ability to visualize mathematical concepts, the heretofore hopeless student is able to manipulate even the most abstract concepts; Nastya becomes an unorthodox but superior mathematician.

Isaac Asimov's ''Foundation's Edge'' is the first new novel published by the popular author in 10 years. Despite the fact that this is the fourth book in the memorable ''Foundation'' series, the new reader will find that it stands on its own.

Central to the story is the fact that two groups, or ''foundations'' of scientists, each at first unaware of the existence of the other, work in isolation carrying out their purposes as set out in the Selden Plan. This scheme aims to limit the time that would elapse between the fall of one galactic empire and the establishment of another.

''Foundation's Edge'' takes up the story as a new enemy threatens to bring all humanity to its knees, while the two foundations of scientists, each now aware of the other's existence, are dealing with xenophobia and power struggles between themselves.

The key action of the novel concerns the travels of a First Foundation councilman, Golan Trevize, who undertakes to discover the location of the Second Foundation. Provided with an impressive spaceship and accompanied by a professor whose dream is to discover humanity's lost home world, Trevize develops his capacities of courage and friendship.

Chases through hyperspace and communion with a remarkable computer bring back a sense of the marvelous for those who like a few technological wonders in their science fiction. Humorous dialogue is employed to develop the personal story of the growth of respect between a driven politician and a gentle professor. This is a satisfying exploration of outer and inner space.

''The Fall of the Shell'' is another novel that stands on its own, although it is the fourth in a series. Written by Prof. Paul O. Williams of Principia College, ''The Pelbar Cycle'' focuses on the regrowth of human societies after a nuclear holocaust.

In ''The Fall of the Shell'' we see a fortress society dominated by women who see themselves as natural administrators, while men are thought to be biologically destined laborers, due to their more sturdy physiques. A self-important, narrow-minded leader called Udge has twisted the well-conceived idealism of the city's founder, Craydor, to keep her society bound to obsolete conventions even in the face of enemy attack.

The action of the novel centers on the adventures of twin brothers, each of whose exploits are told in parallel narratives. Having inadvertently aroused the ire of a high-ranking government official, the intellectual brother, Brudoer, is imprisoned in the cellar of the city, only to find that here lie the true foundations of Craydor's idealism. Brudoer deciphers the founder's inspiring messages, built into the walls of the prison cells, while bearing up under physical punishment.

Meanwhile, Brudoer's twin, Gamwyn, seeks to make retribution for the inadvertent error. A hazardous quest finds Gamwyn equal to a great variety of challenges and able to return to his city at the moment of ultimate crisis. Gamwyn aids his brother in establishing a new order which treats all people, men and women, strangers and citizens, as equals.