Author Stephen Walker: Yuri Gagarin sat on top of a ballistic missile
When Yuri Gagarin became the first man in space 60 years ago, his chances of survival were only estimated to be less than 50:50, author Stephen Walker has told BBC World News.
Mr Walker, whose book, Beyond, tells the story of Yuri Gagarin's mission, says the cosmonaut was launched into space sitting at the top of a ballistic missile crouched in the area that would normally hold the nuclear warhead.
"It is absolutely incredible how dangerous that flight was. This is the first man to sit on top of the most powerful intercontinental ballistic missile in the world. You are talking about a missile that could reach New York from the USSR and basically blow it up.
"There were many really quite gruesome ways in which he could have been killed on that extraordinary flight around the world," he said.