He was known to be an erratic, almost reckless driver of his electric wheelchair, and Hawking insisted his injuries were not caused by abuse. No action was taken.
In 2007, he became the first quadriplegic to experience weightlessness on board the so-called "vomit comet", a modified plane specially designed to simulate zero gravity. He said he did it to encourage interest in space travel.
"I believe that life on Earth is at an ever-increasing risk of being wiped out by a disaster such as sudden nuclear war, a genetically engineered virus, or other dangers. I think the human race has no future if it doesn't go into space. I therefore want to encourage public interest in space."
In 2014, the film The Theory of Everything was released, based on Jane Hawking's account of their courtship and marriage. Hawking himself met Eddie Redmayne as part of the actor's preparation for taking on the role of the scientist.
In a series for the Discovery Channel, he said it was perfectly rational to assume there was intelligent life elsewhere but warned that aliens might just raid earth of its resources and then move on.
He once wrote that he had motor neurone disease for practically all his adult life but said that it had not stopped him having an attractive family and being successful in his work.
"It shows," he said, "that one need not lose hope."