Gagarine blasts a crumbling French housing estate into orbit

► Gagarine is in UK cinemas from 24 September.

While Ladj Ly’s recent César-winning Les Misérables trenchantly examined the milieu of France’s housing projects via their residents’ fractious interactions with the police, début writer-director duo Fanny Liatard and Jérémy Trouilh here take an entirely different route to giving value to the lives of the socially marginalised. Opening newsreel footage of the Soviet cosmonaut Yuri Gagarin facing cheering crowds at the 1963 opening of the Ivry-sur-Seine housing complex named in his honour leaves us in no doubt the Cité Gagarine is a real place. Images capture his military uniform sprinkled with celebratory confetti, and the faces of the assembled locals manifest sheer elation (and perhaps even a bit of disbelief!) that this global icon is planting a tree in their little patch on the outskirts of Paris.

By 2019, however, the civic idealism that brought the development into being is a distant memory. Subsidence issues and the troubling legacy of asbestos means it faces demolition, notwithstanding the opinions of the mainly immigrant inhabitants: they don’t all love the place, but many do, and it is embedded in the affections of Black teenager Youri, who beats the chest of his Côte d’Ivoire football shirt with the rallying cry ‘Gagarine forever’ and is conducting his own maintenance programme using bits of scrap, in the forlorn hope that the place can be saved from the bulldozers.

In the event, he’s destined to stay behind as a sort of stowaway when the flats are evacuated. The marvel of the film is that it allows the audience to view Gagarine through Youri’s eyes; from a perspective shaped by an obsession with sci-fi and science, he sees the place not as some relic of a Corbusier-inspired era of public housing construction, but as if it were some massive space station, tethered to the ground yet perhaps offering a tantalising possibility of off-Earth escape. Remarkably, Liatard and Trouilh make this leap of the imagination surprisingly relatable, with inventive camera angles creating visual rhymes, for instance, between the building’s grid-like fenestration and the real International Space Station’s massive solar panels, plus bold use of colour recalling classic sci-fi cinema – there’s much of the vivid red Kubrick used as a leitmotiv in 2001: A Space Odyssey. Newcomer Alséni Bathily’s captivating central performance draws us into his world too: in him we see the wily projects kid and can discern a profound vein of Spielbergian galactic wonder. Above all, he shows us that affecting capacity – registered in, say, Jacques Tati’s films, or the songs of the youthful Jonathan Richman – to view an unlovely urban environment with an infectious sense of joy.

Then again, perhaps he doesn’t have that much choice. His dad’s long departed, and his mum has left him to his own devices while she shacks up with her new lover, keeping her phone on voicemail to exacerbate her son’s distress. Youri’s piercing feelings of abandonment find strong echoes in the plight of his ethnically diverse neighbours, from West or North Africa or the Middle East, as they bristle against administrative apathy in the crumbling apartment blocks. Moreover, awareness of the precariousness of his existence is heightened by the police’s treatment of the local Roma community, destroying their encampment to move them on. There’s a clear-eyed view here of the apparent racial and cultural contours of social marginalisation, which perhaps balances out the film’s occasionally saccharine whimsy elsewhere – the slightly-too-good-to-be-true central characterisation, an unlikely Morse-code angle in the borderline twee romance with Lyna Khoudri’s teenage Roma beauty Diana. Still, given the story’s basis in a sharply delineated social context, any suggestion that the fanciful space-themed conceit represents arty filmmakers larding wish-fulfilment over a selection of marginalised communities won’t really wash. While the high-stakes finale shows Youri’s hallucinatory view of the block at its most imaginatively enveloping – exquisitely, ecstatically rendered – it also places him in very present jeopardy, as the whole place is literally about to blow.

Gagarine transports us, allowing us to see the magical in the real but, more importantly, it never forgets that this is just one story about the Cité. The film cannily intercuts nostalgically vivid vintage home-movie footage and adds the audio testimonies of real past residents, giving weight to families’ profound and poignant memories of making their homes here (and thanking them in the end credits for their generosity). Much as we’re smitten with Youri’s mind-altering perspective, we’re left in no doubt that these are the lives that really matter.