The Martian was recommended to me by Sarah and Michael during the last meeting of the Cardiff Scifi & Fantasy Book Club. I'm hugely grateful for the recommendation - it was a superb read! The book came up because we were discussing Ringworld, and hard / credible SF. The Martian was given ass an example of current / recent hard SF.
The book starts as Mark Watney, our hero, regains consciousness and discovers that his crew mates have abandoned him and flown back to earth without him. It's unintentional: there was a storm, he had an accident and they were convinced he was dead, while their own lives were in danger, so they took off. Alone on Mars, with only the limited resources left behind by their abandoned mission, he has to find a way to survive.
What makes the Martian so readable is that it is completely and utterly convincing. It's a tale of overcoming one crisis after another by limited means that would be available on this kind of mission. Comparable to the movie Apollo 13 in some regards, only with a much larger scope and a much heavier reliance on one man's ingenuity rather than the thinking power of huge teams on Earth.
It really helps that Mark Watney has a sense of humour and an indomitable disposition. He might curse and (briefly) panic, but whenever disasters strike, he always finds a way to break down the problem into steps and smaller tasks, until he can solve each task in turn. Retaining his sense of humour throughout is a massive help - this could just as easily have been a novel of utmost seriousness and grim determination. Instead, it is a fun novel about a man stranded on Mars.
Other characters by and large also have a sense of humour and mischief. Basically, they're all hugely intelligent and most can be quite witty. It's easy to like and identify with everyone, because everyone is united in common purpose and almost everyone is funny: like the Scooby Gang in the heydays of Buffy.
That said, if you're after complex character studies and a new perspective on the human condition and deep and meaningful literature, this is not the book for you. It's a superb, fun, thrilling read, but it does not go out of its way to chase literary merit. Characters don't learn valuable lessons about life. There might be some gazing out of windows forlornly going on, but it happens off-stage.
There were a few times when I was a little perplexed - Mark talks about liters of gases when calculating chemical reactions, but surely they have different densities and it's mols of gases he should be calculating with? That aside, the book is superbly believable. It is full of spirit and many a "hooray!" moment, and a good few "OMG!! Noooooo!!!!" moments.
I can't wait for mankind to shoot someone to Mars, and I'd be mighty curious what would happen if someone got abandoned there by accident...