To some, he is an eccentric billionaire inventor who dreams of colonising Mars, cartoon-style transport systems, and other futuristic enterprises. To others, he is simply an arsehole.
Elon Musk has said previously that he would like to send a human mission to Mars by the year 2025 - but on a one way trip. Nevertheless thousands of foolish or desperate people have signed up to his suicide mission despite the risks.
There is no life on Mars, or any air for that matter. Anyone hoping to survive there would have to take all their oxygen and food with them, as well as the means to produce more for as long as they expected to live.
This week a childhood friend of Musk, called Jethron Gland, talked about what Musk was like when he was younger. "Elon was a total sicko," he said. "He liked to put ants on rocks while the tide was coming in and watch them drown. He even sealed his pet hamster into his glass cage to watch him die. He often talked about having his own mother buried alive in a coffin with a camera inside."
Gland was cynical about the Mars mission. "If you sign up for it, you'll just be another victim of Musk's weird fetish for watching people die slowly. He gets really horny for it."
Elon Musk was not available for interview but a spokesperson said that if we went to Mars then he might talk to us.