Eight go mad in Arizona: how a lockdown experiment went horribly wrong

In the 1990s, a troupe of hippies spent two years sealed inside a dome called Biosphere 2. They ended up starving and gasping for breath. As a new documentary Spaceship Earth tells their story, we meet the biospherians'

It sounds like a sci-fi movie, or the weirdest series of Big Brother ever. Eight volunteers wearing snazzy red jumpsuits seal themselves into a hi-tech glasshouse that's meant to perfectly replicate Earth's ecosystems. They end up starving, gasping for air and at each other's throats - while the world's media looks on.

But the Biosphere 2 experiment really did happen. Running from 1991 to 1993, it is remembered as a failure, if it is remembered at all - a hubristic, pseudo-scientific experiment that was never going to accomplish its mission. However, as the new documentary Spaceship Earth shows, the escapade is a cautionary tale, now that the outside world - Biosphere 1, if you prefer - is itself coming to resemble an apocalyptic sci-fi world. Looking back, it's amazing that Biosphere 2 even happened at all, not least because the people behind it started out as a hippy theatre group.