Every 45 minutes Major Tim Peake will see a sunrise, or a sunset, regular as clockwork. At 17,500 miles an hour, he will orbit the earth 16 times a day. His new home is at one and the same time an office, workshop, gymnasium, laboratory, mess deck and dormitory, connected by cylindrical corridors and he will commute to work each day effortlessly, floating in microgravity. One of the most demanding things he will have to do is exercise to keep his muscle tissue working at all: most of us are not aware of this, but the tug of gravity keeps even the idlest of earthbound humans moderately fit. Astronauts have to exercise hard, but after months in microgravity most of them have difficulty even standing up once they return to Earth.
Major Peake will gain in stature, and not just because of his elevated position: astronauts get a chance to walk tall in orbit. Most human beings get out of bed slightly taller than when they retired, slightly crushed by gravity’s remorseless tug. Astronauts stay at their full height all the time and don’t use a bed.
Almost the first thing he will want to do on arrival at the ISS is spend a penny: his bodily fluids won’t know where they should be and will tend to collect in his upper torso. His kidneys will send a relatively urgent message. He will have access to a Russian-made zero-gravity toilet in which the wastes are sluiced away not by water but by air, and although what are politely called solids are shipped back towards Earth with the returning supply ships; any urine will be filtered, recycled and returned as drinking or washing water.
He may feel weary without feeling he wants to sleep, because he will be divorced from the 24-hour cycle that most of us are accustomed to. Indeed, the early astronauts often had to be told when to sleep. He may feel nauseous – the first man to vomit in space was the Soviet cosmonaut Gherman Titov in 1961 – and many since have reported uncomfortable symptoms, but at least he will be able to enjoy his food and swallow comfortably. Yuri Gargarin, the first man in orbit that year, nourished himself with two toothpaste tubes of meat puree and one of chocolate. Modern astronauts and cosmonauts have some access to fresh food, delivered with the supply ship, but much of the diet in orbit has to be rehydrated; the bread is thermo-stabilised and the meat is preserved by irradiation. And although space station provender is more various and imaginative than it used to be – and sometimes reflects national traditions of the astronaut tenants - it still has to be prepared and packaged in ways that keep the wrappings light and stop the crumbs floating away into the air conditioning system.
But the rations are no longer quite so Spartan: in 2015 the Italian astronaut Samantha Cristoforetti became the first person to use a specially-designed espresso machine and sip freshly-brewed coffee in space.
Major Peake will eat at a communal table – the space station furniture maintains a tradition of floor and ceiling – but that doesn’t mean he has to sit at it, because “up” and “down” become meaningless in microgravity. But microgravity also makes taking a shower in space awkward. There is a closed shower cubicle, but the water droplets don’t flow down a plughole: vacuum suction has to collect and filter them for re-use. There is plenty to do. The station must be maintained, the systems checked, reports made and order restored after each event, and even the most mundane actions – shaving, brushing teeth, washing with a sponge – require care. Astronauts and cosmonauts miss their children, their families and their friends on earth, but there are few complaints about boredom.
