Ringworld


Larry Niven - 1970
    Pierson's puppeteers, the aliens who discovered it, are understandably wary of encountering the builders of such an immense structure and have assembled a team of two humans, a mad puppeteer and a kzin, a huge cat-like alien, to explore it. But a crash landing on the vast edifice forces the crew on a desperate and dangerous trek across the Ringworld.

The Forever War


Joe Haldeman - 1974
    A reluctant conscript drafted into an elite Military unit, Private William Mandella has been propelled through space and time to fight in the distant thousand-year conflict; to perform his duties without rancor and even rise up through military ranks. Pvt. Mandella is willing to do whatever it takes to survive the ordeal and return home. But "home" may be even more terrifying than battle, because, thanks to the time dilation caused by space travel, Mandella is aging months while the Earth he left behind is aging centuries.

Gateway


Frederik Pohl - 1977
    and on reaches of unimaginable horror. When prospector Robinette Broadhead went out to Gateway on the Heechee spacecraft, he decided he would know which was the right mission to make him his fortune. Three missions later, now famous and permanently rich, Rob Broadhead has to face what happened to him and what he has become... in a journey into himself as perilous and even more horrifying than the nightmare trip through the interstellar void that he drove himself to take!

The Gods Themselves


Isaac Asimov - 1972
    But even free energy has a price. The transference process itself will eventually lead to the destruction of the Earth's Sun--and of Earth itself.Only a few know the terrifying truth--an outcast Earth scientist, a rebellious alien inhabitant of a dying planet, a lunar-born human intuitionist who senses the imminent annihilation of the Sun.  They know the truth--but who will listen?  They have foreseen the cost of abundant energy--but who will believe?  These few beings, human and alien, hold the key to the Earth's survival.

The Mountains of Mourning


Lois McMaster Bujold - 1989
    [Publisher's Note: The Mountains of Mourning was originally published as a stand-alone novella in the May 1989 issue of Analog. It was then included as the first of three novellas that make up the novel Borders of Infinity (October 1989). For the novel, Ms. Bujold added a short "framing story" that tied the three novellas together by setting up each one as a flashback that Miles experiences while recovering from bone-replacement surgery. Fictionwise is publishing these novellas separately, but we decided to leave in Ms. Bujold's short framing story for those who may also wish to read the other two novellas (Labyrinth and The Borders of Infinity).] Locus Poll Award Nominee, Nebula Award Winner, Hugo Award Winner, SF Chronicle Poll Nominee

Rendezvous with Rama


Arthur C. Clarke - 1973
    It is huge, weighing more than ten trillion tons. And it is hurtling through the solar system at an inconceivable speed. Then a space probe confirms the unthinkable: Rama is no natural object. It is, incredibly, an interstellar spacecraft. Space explorers and planet-bound scientists alike prepare for mankind's first encounter with alien intelligence. It will kindle their wildest dreams... and fan their darkest fears. For no one knows who the Ramans are or why they have come. And now the moment of rendezvous awaits — just behind a Raman airlock door.

A Fire Upon the Deep


Vernor Vinge - 1992
    A Fire upon the Deep is the big, breakout book that fulfills the promise of Vinge's career to date: a gripping tale of galactic war told on a cosmic scale.Thousands of years hence, many races inhabit a universe where a mind's potential is determined by its location in space, from superintelligent entities in the Transcend, to the limited minds of the Unthinking Depths, where only simple creatures and technology can function. Nobody knows what strange force partitioned space into these "regions of thought," but when the warring Straumli realm use an ancient Transcendent artifact as a weapon, they unwittingly unleash an awesome power that destroys thousands of worlds and enslaves all natural and artificial intelligence.Fleeing the threat, a family of scientists, including two children, are taken captive by the Tines, an alien race with a harsh medieval culture, and used as pawns in a ruthless power struggle. A rescue mission, not entirely composed of humans, must rescue the children-and a secret that may save the rest of interstellar civilization.

The Left Hand of Darkness


Ursula K. Le Guin - 1969
    His goal is to facilitate Winter's inclusion in a growing intergalactic civilization. But to do so he must bridge the gulf between his own views and those of the completely dissimilar culture that he encounters.Embracing the aspects of psychology, society, and human emotion on an alien world, The Left Hand of Darkness stands as a landmark achievement in the annals of intellectual science fiction.

Hyperion


Dan Simmons - 1989
    There are those who worship it. There are those who fear it. And there are those who have vowed to destroy it. In the Valley of the Time Tombs, where huge, brooding structures move backward through time, the Shrike waits for them all. On the eve of Armageddon, with the entire galaxy at war, seven pilgrims set forth on a final voyage to Hyperion seeking the answers to the unsolved riddles of their lives. Each carries a desperate hope—and a terrible secret. And one may hold the fate of humanity in his hands.

A Time of Changes


Robert Silverberg - 1971
    One of the strangest is on Borthan, where the founding settlers established the Covenant, which teaches that the self is to be despised, and forbids anyone to reveal his innermost thoughts or feelings to another. On Borthan, the filthiest obscenities imaginable are the words "I" and "me." For the heinous crime of "self-baring," apostates have always paid with exile or death, but after his eyes are opened by a visitor from Earth, Kinnall Darival, prince of Salla, risks everything to teach his people the real meaning of being human..

Starship Troopers


Robert A. Heinlein - 1959
    We just call it “The Bug War." Everything up to then and still later were "incidents," "patrols," or "police actions." However, you are just as dead if you buy the farm in an "incident" as you are if you buy it in a declared war...In one of Robert A. Heinlein’s most controversial bestsellers, a recruit of the future goes through the toughest boot camp in the Universe—and into battle with the Terran Mobile Infantry against mankind’s most alarming enemy.

Star Maker


Olaf Stapledon - 1937
    The book describes a history of life in the universe, dwarfing in scale Stapledon's previous book, Last and First Men (1930), a history of the human species over two billion years. Star Maker tackles philosophical themes such as the essence of life, of birth, decay and death, and the relationship between creation and creator. A pervading theme is that of progressive unity within and between different civilizations. Some of the elements and themes briefly discussed prefigure later fiction concerning genetic engineering and alien life forms. Arthur C. Clarke considered Star Maker to be one of the finest works of science fiction ever written.

Ancillary Justice


Ann Leckie - 2013
    On a remote, icy planet, the soldier known as Breq is drawing closer to completing her quest.Once, she was the Justice of Toren - a colossal starship with an artificial intelligence linking thousands of soldiers in the service of the Radch, the empire that conquered the galaxy.Now, an act of treachery has ripped it all away, leaving her with one fragile human body, unanswered questions, and a burning desire for vengeance.

Babel-17


Samuel R. Delany - 1966
    Humanity, which has spread throughout the universe, is involved in a war with the Invaders, who have been covertly assassinating officials and sabotaging spaceships. The only clues humanity has to go on are strange alien messages that have been intercepted in space. Poet and linguist Rydra Wong is determined to understand the language and stop the alien threat. (Paul Goat Allen)

Red Mars


Kim Stanley Robinson - 1992
    For centuries, Mars has beckoned humans to conquer its hostile climate. Now, in 2026, a group of 100 colonists is about to fulfill that destiny.John Boone, Maya Toitavna, Frank Chalmers & Arkady Bogdanov lead a terraforming mission. For some, Mars will become a passion driving them to daring acts of courage & madness. For others it offers an opportunity to strip the planet of its riches. For the genetic alchemists, it presents a chance to create a biomedical miracle, a breakthrough that could change all we know about life & death. The colonists orbit giant satellite mirrors to reflect light to the surface. Black dust sprinkled on the polar caps will capture warmth. Massive tunnels, kilometers deep, will be drilled into the mantle to create stupendous vents of hot gases. Against this backdrop of epic upheaval, rivalries, loves & friendships will form & fall to pieces--for there are those who will fight to the death to prevent Mars from ever being changed.Brilliantly imagined, breathtaking in scope & ingenuity, Red Mars is an epic scientific saga, chronicling the next step in evolution, creating a world in its entirety. It shows a future, with both glory & tarnish, that awes with complexity & inspires with vision.