The book is usually better than the movie. Since I haven't seen The Martian movie yet, I figured I'd better read the book first. The book is very good.
I think the general plot of The Martian is well known enough due to the popularity of the film adaptation -- astronaut gets stranded on Mars, must fight to survive, must make a load of potatoes. In essence, The Martian amounts to a series of obstacles that are overcome by insanely quick thinking from an insanely smart main character.
Mark Watney is the astronaut who gets stranded; this happens when his crew is fleeing a dangerous sand storm that will cut their 30-day mission short. Watney is hit by flying debris and is thrown out of sight from the rest of his crew, with debris having stabbed through his space suit, impaling him. He thinks the crew assumed him dead and left the planet without him, but he survived by the slimmest of odds.
From there, Watney is faced with the tall order of surviving on Mars. The first thing we establish is that he's entirely alone: The communications dish from the Hab, the crew's Mars shelter, was destroyed in the sand storm that drove the crew off the red planet. So no one knows he's alive, which means no one's coming back for him, which means -- as Mark quickly figures out -- he has to survive for four years until the next mission to Mars shows up on the planet. That mission will land at a site about 3,000 kilometers away from his current location, so he also has to figure out how to get there.
"If the oxygenator breaks down, I’ll suffocate. If the water reclaimer breaks down, I’ll die of thirst. If the Hab breaches, I’ll just kind of explode. If none of those things happen, I’ll eventually run out of food and starve to death."
Andy Weir paces this book really cleverly. You get Watney's side of the story in the form of log entries. He posts in his log super regularly at first, but eventually he neglects to write everyday -- just as you or I would, in all likelihood. Meanwhile, you get the story from Earth in the form of real-time dialogue. The smart people who work at NASA do figure out that Watney is alive based on the content of satellite images, and are able to communicate directly with Watney once he finds the ancient Mars Pathfinder rover and uses that to transmit basic messages to NASA.
This ability to communicate is take away when Pathfinder is accidentally fried during some haphazard construction. But before this all takes place, Watney has to figure out how to fulfill his basic needs. He has a lot of food leftover since there was enough to feed six people for 30 days and those six people only wound up being on Mars for a few days. But it won't last him nearly as long as he needs to live, so he uses his botany skills -- yes, this engineer / astronaut is also an accomplished botanist -- to grow loads of potatoes using Martian soil.
Reading as Watney figures out these problems is fascinating. Weir dedicates a LOT of page space to the actual science and math that Watney is employing. This lends plenty of texture to a story that throws obstacle after obstacle at Watney -- including his shelter nearly blowing up, and one occasion on which his shelter is bridged completely. The fact that Watney winds up surviving and being rescued by his crew, which flies back to Mars to save him, is realistic because of the math and science that we see him figure out in real time, many times on the fly. This is obviously a super smart person -- Watney is an engineer / astronaut / botanist -- and his creative thinking on the fly, along with an acute understanding on exactly what resources he has available to him, is enough to keep him barely alive in the rough moments. He's also pretty chill for a guy who is stranded on Mars:
"Teddy swiveled his chair and looked out the window to the sky beyond. Night was edging in. 'What must it be like?' he pondered. 'He’s stuck out there. He thinks he’s totally alone and that we all gave up on him. What kind of effect does that have on a man’s psychology?' He turned back to Venkat. 'I wonder what he’s thinking right now.'
LOG ENTRY: SOL 61
How come Aquaman can control whales? They’re mammals! Makes no sense."
Given the log entry style of the Watney's side of the story, there are moments when Weir breaks in as a narrator to explain an event. This moments are extremely ominous after it happens for the first time, because Weir rarely narrates something happy in this style. It makes for a wild and fun ending to the story, full of tension and close calls. Would very highly recommend.
The Martian is available as an IRL book and an e-book on Amazon. It's also available on Audible; if you click this link, you can get a free trial of Audible that includes two free audiobooks. Even if you cancel your trial, you'll get to keep these two books. Also: clicking on any of the Amazon links in this post, and purchasing something from them, provides a small percentage kickback to the author of the blog you just read.