Two hundred thousand feet up, things go horribly wrong. An experimental low-orbit spaceplane breaks up on reentry, falling to earth over a trail hundreds of miles long. And in its wake is the beginning of the most important mission in the history of spaceflight.

Here are tales of star-faring adventure, peril, and drama. Here are journeys into the mind-bending landscapes of virtual worlds and alternate realities. Here you'll also find stories of humanity's astounding future on Earth, on Mars, and in the solar system beyond - stories that always get the science right. And Bova's gathering of deeply realized, totally human characters are the heroic, brave, tricky, sometimes dastardly engineers, astronauts, corporate magnates, politicians, and scientists who will make these futures possible.

Welcome to Ringworld, an intermediate step between Dyson Spheres and planets. The gravitational force created by a rotation on its axis of 770 miles per second means no need for a roof. Walls 1,000 miles high at each rim will let in the sun and prevent much air from escaping. Larry Niven's novel, Ringworld, is the winner of the 1970 Hugo Award for Best Novel, the 1970 Nebula Award for Best Novel, and the 1972 Ditmars, an Australian award for Best International Science Fiction.

Earth is an old planet, and her teeming masses are running out of resources - and time. It is up to men such as Jeff Holman to discover a haven for Earth’s millions. Altair VI is one such planet, and Holman is determined to transform this world into one where the human race can survive. Star probes long ago informed Earth that Altair VI had a flourishing ecology with one very tough beast at the top of the food chain, one that will have to be dealt with before the human colony ships arrive. The beast is not only tough, it is as smart as a man. Holman is faced with a soul-wrenching decision - for to make Altair VI habitable for humans, all native life must die.

Stoner knew. The fiery object hurtling toward the Earth was an alien spacecraft. But the world might never know. He was trapped in an iron cordon of secrecy, for the discovery had shattered the world power balance, setting off a brutal struggle for supremacy that raged from the sacred halls of the Vatican to the corridors of the Kremlin and the Pentagon. The forces of fear and treachery would use any weapon at their command, from mind war to sabotage, to keep the world in darkness.

A hero without peer or scruples, Sam Gunn has a nose for trouble, money, and women, though not necessarily in that order. A man with the ego (and stature) of a Napoleon, the business acumen of a P. T. Barnum, and the raging hormones of a teenage boy, Sam is the finest astronaut NASA ever trained and dumped. But more than money, more than women, Sam Gunn loves justice—and he really does love money and women.

The time: 200 years after man's first landing on the Moon. There are permanent populations established on the Moon, Venus, and Mars. Outer space inhabitants have formed a new political entity, the Federation, and between the Federation and Earth a growing rivalry has developed. Earthlight is the story of this emerging conflict.

When Kell and his team return to Earth many years after their departure, they find that their world has changed almost beyond recognition. Not only has a second wave of greenhouse flooding caused sea levels to rise, but society has been changed by the consequences of the climate shift. Few people want to face Jordan Kell's news. He must convince Earth's new rulers that the human race is in danger of extinction unless it acts to forestall the death wave coming from the galaxy's heart.

Vannemar Morgan's dream is to link Earth to the stars with the greatest engineering feat of all time: a 24,000-mile-high space elevator. But first he must solve a million technical, political, and economic problems while allaying the wrath of God. For the only possible site on the planet for Morgans Orbital Tower is the monastery atop the Sacred Mountain of Sri Kanda.

Deadly radiation from a passing comet is about to destroy life on Earth. In desperation, the US government constructs a series of underground shelters to protect as many people as possible. They are expected to be underground for 20 years before returning back to the surface. But can they survive their time within the confines of the underground shelter? And what will they find when they finally emerge?

A preposterous legend, dragons dueling with riggers. Nothing can live in the interdimensional Flux of interstellar space. But in the Flux, visions of the mind converge with reality, and visions can be perilous. When star pilot Jael defies an abusive ship’s master and rigs “the mountain route to Lexis,” dragons indeed appear in the night sky—and challenge her to duel to the death.

Car-En, a ringstation anthropologist on her first Earth field assignment, observes a Viking-like village in the Harz mountains. As Car-En secretly observes the Happdal villagers, she begins to see them as more than research subjects (especially Esper, a handsome bowhunter). When Esper’s sister is taken by an otherwordly sword-wielding white-haired man, she can no longer stand by as a passive witness. Knowing the decision might end her career, she cuts off communication with her advisor and pursues the abductor into the mountains.

The year is 1876. Warring Indian tribes still populate America's western territories, even as lawless gold-rush towns begin to mark the landscape. In much of the country, it is still illegal to espouse evolution. Against this backdrop two monomaniacal paleontologists pillage the Wild West, hunting for dinosaur fossils while surveilling, deceiving, and sabotaging each other in a rivalry that will come to be known as the Bone Wars.

Late in the 21st century, Earth receives what looks like an urgent plea for help from planet Proxima Centauri b in the closest star system to the Sun. Astrophysicists suspect a massive solar flare is about to destroy this heretofore-unknown civilization. Earth's space programs are unequipped to help, but an unscrupulous Russian billionaire launches a secret and highly-specialized spaceship to Proxima b, over four light-years away.

The starship Earthling, filled with thousands of hibernating colonists en route to a new world at Tau Ceti, is stranded beyond the solar system when the ship's three organic mental cores—disembodied human brains that control the vessel's functions—go insane. The emergency skeleton crew sees only one chance for survival: build an artificial consciousness in the Earthling's primary computer that can guide them to their destination—and hope it doesn't destroy the human race.