It's very short. It follows one day in the life of a group of 6 astronauts in a space station, watching the Earth below as they orbit it several times in a day.
It doesn't really have any plot or story. It's literally just a day in the life of these astronauts. Nothing they do is different to any other day.
They're asked to take pictures of a developing weather system on the planet below them. that's about as much plot as this book contains.
The prose is gorgeous, verging on the poetic. The monotony of living in a space station is captured brilliantly without ever feeling monotonous. You could possibly argue that there is some repetitive content in this book, but only in the same way that Beethoven's 5th could be considered repetitive. It's variations on the theme, which sound similar but just different enough to keep the interest. In the case of any direct repetition, it doesn't sound wrong, it's because its the right thing to do at that point and it all sounds beautiful anyway.
I actually thought of that particular comparison a couple of pages before that tune was specifically referenced as one of the pieces of music included on Voyager for alien species to potentially enjoy at some point. The direct reference makes it quite an appropriate analogy IMHO.
It's meandering and plotless and filled with philosophical musings. But thanks to the prose, it's never actually boring. Don't expect action packed sci-fi where the brave astronauts solve all our problems and relax into the mood of the writing and this book becomes a relaxing spa bath of a read.
There are warnings about the way we're treating the planet, and the super-tornado they witness is explained as a result of global warming, but it never feels like the writer is preaching to the reader.
Harvey has a remarkable ear for language and a similar skill at transcribing it to the page. Whether she can write a story or not, I'm not sure. But this is a book you experience rather than read. If you'd told me before I read this that I would like a meditation on infinity, man's place inside it and the impact we're having on our environment as much as I enjoyed this, I'd have laughed at you. A true triumph, in the best possible sense of the word, of style over content (although that said, she does make the content rather thought provoking and interesting in any case).
As per my previous comments about Booker winners, this is not necessarily an easy read. You have to let the mood of the writing take you, then it will take you to orbit if you let it.