When Yuri Gagarin became the first human in space in 1961, he barely had time on his 108-minute flight to tuck into the tubes of meat paste provided in case he got peckish. Compare that with Russian cosmonaut Valeri Polyakov, who clocked up 437 days in continuous orbit between 1994 and 1995.
Space travellers like Polyakov have to deal with not just with the drama and awesome demands of life in orbit, but the day-in, day-out monotony of everyday tasks carried out tens of miles above the Earth’s surface and in absolute weightlessness. For instance, how do you take a wash in zero gravity? More delicately, what kind of toilets do you install in spacecraft when there is no gravity to help things flush?
Life in weightlessness means a permanently stuffy nose and impaired smell and taste – space travellers are said to crave spicy, well-seasoned food – and the threats of wasted muscles. Improvised gyms have been set up to ensure the astronauts don’t find their muscles have wasted when they eventually find themselves back on Earth.
Launched 40 years ago in May 1973, Skylab became America's first space station – a three-person laboratory designed to conduct scientific experiments such as the effects of weightlessness and observations of the sun. Almost four decades after, Commander Chris Hadfield became an internet sensation by revealing the day-to-day life of space living to a new generation – from making a peanut butter and honey sandwich to wringing out a wet cloth to his zero-g cover of David Bowie’s Space Oddity. Here’s some more examples of what astronauts have had to experience when they are floating round their tin can...