It’s been a testing year for Elon Musk, the megabillionaire businessman whose businesses seem to reflect his own mind in operating at the outer orbits of possibility. Musk is a busy boy: his companies are trying to redefine motoring ( Tesla), travel ( Hyperloop) and the planet( s) that we call home ( SpaceX). Oh, and there’s all that tweeting to be done. How does he manage it? In an interview with The New York Times earlier this year, Musk revealed that he was regularly working 120-hour weeks – and using insomnia medication Ambien to help him sleep.