Want to supercharge technological innovation? Save democracy? End war? Then colonise the Red Planet, argues Robert Zubrin. The American engineer pictures an idealised version of Renaissance Florence, but in space: a peaceful utopia where streets teem with cafés, bakeries, peddler stalls, taverns and music schools. But his vision differs from that of Elon Musk, one of Dr Zubrin’s early disciples. Though they both want to get to Mars, they disagree over who should be in the cockpit.

Grand visions can be found closer to home, too. In the Victorian era, British intellectuals were seized by the novel idea that brains, not breeding, should determine success. One result was the introduction of an entrance exam for Oxford University’s All Souls College, which was designed to create an intellectual aristocracy chosen by open competition. The test has been dubbed the hardest in the world and “the SAS of academia”. Does it really work?

The International Space Development Conference is an annual jamboree for interplanetary entrepreneurs. It draws space-industry professionals, NASA researchers, rocket-launch obsessives, young dreamers and anyone else hoping one day to live in—or at least profit from—settlements beyond Earth.