World Engines Series by Stephen Baxter

Hundreds of years in the future, on a stagnating and almost empty Earth, a space shuttle pilot from the early days of the 21st century is awoken from the cryogenic sleep he entered after a devastating accident. As he comes to terms with this new world, he begins to realise that their history does not match what he remembers - and that only he may be able to stop the coming catastrophe destined to destroy the planet. Until he meets a young woman who seems to have a drive of her own, and a plan...

Trapped on an alternate Earth, the combined crews of a crashed Russian spaceship, a British expeditionary force and a group of strays from the future must work together to survive, escape, and discover what led them to this point. All are from parallel universes where small changes in history led to different realities, and the tensions between the groups are rising. But some changes were not small... moreTrapped on an alternate Earth, the combined crews of a crashed Russian spaceship, a British expeditionary force and a group of strays from the future must work together to survive, escape, and discover what led them to this point. All are from parallel universes where small changes in history led to different realities, and the tensions between the groups are rising. But some changes were not small. The solar system has been altered, changed, shaped in the various realities, and the World Engineers - unspeakably powerful, completely unknown - are still active. Why have they populated this planet with humanity's ancestors and dinosaurs? What is on the moon of Saturn that gives off such an odd light? And even if they can be found, can they be stopped - and should they be? Malenfant, Deidra and the rest of their party must find a way off the planet, back into space, and into the many dimensions seeking the answer... less