On a Saturday morning in December 2022, Elon Musk summoned finance executives at Twitter, which he had bought six weeks earlier, to a conference call. Then he drilled into a spreadsheet that contained the social media company’s expenditures.

SpaceX’s Starship rocket will be launched for a sixth test flight next week, the latest experiment by the Elon Musk-owned aerospace firm to create reusable spacecraft after a previous test resulted in a “seminal moment” for the company.

The boss of Tesla and the social media site X, Elon Musk, suggested last month at Donald Trump’s rally in New York City that it would be possible to cut “at least $2 trillion” from US government spending by eradicating “waste”.