This slender, gleaming novel depicts a day in the life of six astronauts at the International Space Station – but a day isn’t a day for a crew orbiting Earth at more than 17,000 miles an hour. Space ‘takes their 24 hours and throws 16 days and nights at them in return’.

Weaving a line of philosophical enquiry through her luminous prose has become something of a trademark for Samantha Harvey, who probed the elasticity of time through a portrayal of Alzheimer’s disease in her prize-winning debut The Wilderness and, in All is Song, transported Socrates to the 21st century. In Orbital, her sixth book, she explores time again, especially the dissonance between how we experience it bodily – insisted upon by mission control’s prescriptive schedule enforcing diurnal rhythms – and mentally. ‘The mind goes free within the first week’, leaving the astronauts struggling to gauge the length of a minute.

As the division of day and night is complicated by space travel, so are Earth’s geographical and political partitions: ‘Continents run into each other like overgrown gardens… the Earth feels – not small, but almost endlessly connected, an epic poem of flowing verses.’ Much of Orbital reads like nature writing from the extraordinary perspective of space, but Harvey punctuates these vivid, lush passages with moments of wry observation and humour. The two space station toilets are split along Cold War lines. ‘Because of ongoing political disputes, please use your own national toilet,’ reads the sign on the American one’s door: ‘The idea of a national toilet has caused some amusement among the crew,’ we are told. ‘I’m just going to take a national pee, Shaun will say. Or Roman: Guys, I’m going to go and do one for Russia.’

The crew exercise ‘flagrant disregard of these edicts’ and share toilets as well as food, along with ‘each other’s overused air’. They feel they are ‘merging’ with one another, and Harvey explores how we preserve or dissolve the boundaries to our internal lives when in such close physical proximity. This is intimately expressed when one of the crew, Chie, tells a story about her mother, who has died while Chie has been in space: ‘Anton finds himself crying, and his tears form four droplets which float away from his eyes and which he and Chie catch in the palms of their hands.’

They mourn for Chie’s mother and also for Earth, ‘a mother waiting for her children to return’. The astronauts witness a typhoon devastate the Philippines and notice how the planet – ‘this thing of such miraculous and bizarre loveliness’ – is also ‘contoured and landscaped by want’. Sorrow for the human destruction of the planet is tempered by hope born from the same ‘restless spirit of endeavour’. Roman wonders: ‘Maybe there’s another parent-planet – Earth was our mother and Mars, or somewhere, will be our father.’ 

Harvey demonstrates in this novel how binary divisions are at once meaningless and alive with hidden complexities. She invites us to step away from the choice between despair or hope for our future and embrace the creative potential of them together.