Music conveys the emotions of all the characters: Augustine [Clooney], who is very ill; the little girl [Caoilinn Springall], who doesn’t speak; the crew in the spaceship".

Desplat wanted to something "gentle and contemplative but also being a "tragedy about death" referring to the end of earth which was "more internal, about regret and suffering and the future of mankind, but seen through the eyes of real people".

For the astronauts' first spacewalk, Clooney demanded "very quiet, very slow strings play" in a suspended and motionless way, as it "creates a kind of silence without being silent".

[4] He felt the biggest challenge was to balance the human aspects with the constant sense of danger, both in earth and space where "there is a warmth between the characters, solidarity and friendship and benevolence.

[5][6] Due to the COVID-19 pandemic, Desplat had to record the sessions separately, which twists for the musicians to the perception of the "overall orchestral sound, dynamics, intonation, phrasing music" making it frustrating to the director.

[9] David Rooney of The Hollywood Reporter wrote "if Alexandre Desplat’s rich orchestral score often leans too hard on the heart-tugging sentiment, its surging power in dramatic moments is undeniable.

There are times here where Alexandre Desplat is scoring from the bleakest possible place, combining orchestral and electronic textures in a way that is beautiful, but tinged with bitterness, regret, and no small part of desperation.

"[14] Richard Lawson of Vanity Fair felt that Desplat's score sounds like a "children’s fable" or even resemblng Alan Silvestri's main theme from Contact (1997).