Aurora by Kim Stanley Robinson (Orbit, £18.99).

Kim Stanley Robinson, one of the best science fiction writers around, tackles big subjects in his novels.

He is perhaps best known for his brilliant Mars trilogy, which focused on attempts to terraform the Red Planet. Full of complex and brilliant characters, some strong science and packed with incident, the trilogy remains in my top five sci-fi books.

Aurora covers some similar themes - attempts by humanity to colonise other planets, the problems faced by lengthy space missions, the fragility of society and the tendency for communities to break down over time into rebellion and revolution.

The clever twist in this book is that, after a 169-year journey to Aurora, the occupants of the starship - who have never known another home apart from the space ship, find the planet is toxic to humans and the first settlers are wiped out within months.

The remaining travellers, incuding main protagonist Freya, daughter of the ship's lately deceased chief engineer, have to decide what to do. Should they stay and try to settle on another planet, or head back to Earth?

In the end, they split and the ship starts to make the long journey back to the mother planet.

This is when it starts getting really interesting as the aged ship starts to malfunction, crops in the various biomes fail and food becomes scarce. The travellers are forced to put themselves into deep freeze isolaiton, entrusting their futures to the increasingly sensient Ship, which actually narrates the whole story.

As readers it is easy to grown fond of the ship, which wrestles with what it means to be 'conscious', while at the same time loyally tries to find a way to get the ailing crew back home.

Things get hairy as matters have deteiorated back on Earth, where polar icecaps have melted. The original laser which catapulted the ship into space, in no longer working and so will not be able to be used to sufficiently slow the incoming ship down as it approaches the solar system.

This is a big book, full of ideas. It is quite short on characterisation, choosing instead to focus on a narrative of events. It also has a very low-key ending.

But, like all Robinson's novels, it remains a hugely compelling read.