Orbital by Samantha Harvey, the only British writer shortlisted this year, has won the 2024 Booker prize, the UK’s most prestigious prize for fiction.

Harvey’s tale of six fictional astronauts on the International Space Station was “unanimously” chosen as the winner after a “proper day” considering the six-strong shortlist, according to judging chair, the artist and author Edmund de Waal. “Our unanimity about Orbital recognises its beauty and ambition. It reflects Harvey’s extraordinary intensity of attention to the precious and precarious world we share”.

“I was not expecting that,” said Harvey in her acceptance speech. “We were told that we weren’t allowed to swear in our speech, so there goes my speech. It was just one swear word 150 times.”

She went on to dedicate her win to those who “speak for and not against the Earth, for and not against the dignity of other humans, other life, and all the people who speak for, and call for, and work for peace”.

Orbital, which was published last November and is now available in paperback, was the highest-selling book of the shortlist in the run-up to the winner announcement, with 29,000 copies sold in the UK this year. The book, which follows its characters over the course of a day as they experience 16 sunrises and 16 sunsets, is a “finely crafted meditation on the Earth, beauty and human aspiration”, wrote Alexandra Harris in her Guardian review.

At 136 pages long, Orbital is the second-shortest book to win the prize in its history; it is four pages longer than Offshore by Penelope Fitzgerald, which won in 1979. Asked whether the panel’s choice is a vote in favour of short books, De Waal said “absolutely not”, adding that Orbital is “the right length of book for what it’s trying to achieve”.

Harvey said that she nearly gave up on writing Orbital because she thought: “Why on earth would anybody want to hear from a woman at her desk in Wiltshire writing about space, imagining what it’s like being in space, when people have actually been there? I lost my nerve with it, I thought, I don’t have the authority to write this book.”

Orbital was bookmaker William Hill’s joint favourite to win, along with Percival Everett’s James, a reimagining of The Adventures of Huckleberry Finn from the perspective of the enslaved Jim. James was the favourite at Ladbrokes, and critics agreed that Everett was most likely to take home the prize. With Everett being the only man on the shortlist, this year marked the first time that five women were shortlisted in the prize’s 55-year history. Taking home the £50,000 prize on Tuesday evening, Harvey has become the first woman to win the award in five years. Asked what she would spend the prize money on, Harvey said that she needs a new bike.

Harvey was previously longlisted for the Booker prize in 2009 for her debut novel, The Wilderness. Orbital is her fifth, following All Is Song, Dear Thief and The Western Wind. She has also written a memoir on insomnia, The Shapeless Unease, which was published in 2020.

Shortlisted with Harvey and Everett were Rachel Kushner for Creation Lake, Anne Michaels for Held, Yael van der Wouden for The Safekeep and Charlotte Wood for Stone Yard Devotional.

Alongside De Waal on this year’s judging panel were novelists Sara Collins and Yiyun Li, Guardian fiction editor Justine Jordan, and musician Nitin Sawhney. “As judges we were determined to find a book that moved us, a book that had capaciousness and resonance, that we are compelled to share,” said De Waal. “We wanted everything.”

“Orbital is our book,” he added. “Everyone and no one is the subject, as six astronauts in the International Space Station circle the Earth observing the passages of weather across the fragility of borders and time zones. With her language of lyricism and acuity, Harvey makes our world strange and new for us.”

The winner was chosen from 156 books published between 1 October 2023 and 30 September 2024. To be eligible, books had to have been written originally in English by an author of any nationality, and published in the UK or Ireland. Before 2014, only books by writers from the Commonwealth, Ireland and Zimbabwe were eligible.

One of last year’s judges, the comedian Robert Webb, called the task of reading every submitted book “impossible”, adding that “you finish as many as you can and the other ones you put to one side after a respectable but undisclosed fraction has been read.” However, De Waal said this year’s judges “read every single one fully”.

Last year, Irish writer Paul Lynch took home the award for his dystopian novel Prophet Song. Other recent winners include Shehan Karunatilaka, Damon Galgut and Douglas Stuart. The last time a woman was announced as winner was in 2019, when Bernardine Evaristo and Margaret Atwood were named joint winners.