10 Things We Learnt About Space from British Astronaut Tim Peake
Discover the wonders and quirks of life on the International Space Station.

1. Space smells like a British barbecue
Every astronaut has their own interpretation of the unique smell of space. Germany’s Alexander Gerst claims it smells “like a mixture between walnuts and the brake pads of my motorbike.” NASA’s Donald Pettit compares it to “sweet smelling welding fumes.” But whenever British astronaut Tim Peake opened the airlock of the International Space Station (ISS), during his six-month stay from December 2015 to June 2016, the scent reminded him of “a British summer barbecue” or “burning sausages on a charcoal grill.”
One theory is that this metallic smell comes from dying stars, which produce pungent compounds called ‘polycyclic aromatic hydrocarbons’ that linger in space. Whatever the cause, Peake insists it was “a rather pleasant smell.”
2. You can see the Earth’s atmosphere from space
Peake enjoyed a kaleidoscope of majestic sights from the ISS, including the green and red streaks of the aurorae, the sparkling glaciers of Patagonia, and a thunderstorm above South Africa which stretched for hundreds of miles. He could even see the Earth’s atmosphere, which appeared as a thin white band by day and a greenish-orange strip at night.
“I remember thinking, ‘Is that it? You’ve got to be kidding me! Life on Earth owes its existence to that thin strip of gas,’” recalls Peake. Most of the Earth’s air is contained in a narrow band just 16km high. “We’d do well to look after that precious band of life-supporting gas,” he reflects.
3. There are over 100 items on the ISS menu
During his time on the ISS, Peake ate from a menu of over 100 dishes, including sausage patties, maple-top muffins and apricot cobblers. Some meals were freeze-dried. “They are a bit like military rations or camping food and don’t taste too bad,” he notes.
Ten percent of his daily calorie intake came from ‘bonus food’ which the astronauts could request prior to travel. Peake’s treats included bacon sandwiches and feasts devised by British chef Heston Blumenthal. “Canned Alaskan salmon with capers was an absolute favourite,” he writes. “Ingredients such as capers, which explode in your mouth with an intense flavour, work really well in space.”
4. Astronauts sleep like vampires
Crew on the ISS have their own sleeping quarter, about the size of a shower cubicle, where they can wrap themselves in a sleeping bag. Some prefer to be strapped securely to a wall, while others are content to float around. Peake admits he liked “to clip my sleeping bag very loosely to hooks in the wall, then zip myself into the bag and just let myself float.” He would fold his arms across his chest – like a sleeping vampire – within his sleeping bag to prevent them floating upwards as he slept.
5. Space walks give you vertigo
On 15th January 2016 Peake took part in an extravehicular activity (EVA) – or ‘spacewalk’ – to perform repairs to the ISS. Despite working in a deadly void where temperatures can fluctuate from 200 to minus 200 degrees between sunlight and shade, he relished those magical four hours and 43 minutes, “marvelling at how fragile and beautiful Earth looked as it slipped gracefully into shadow.”
Until, that is, he saw Australia pass beneath him. “I felt a sudden tinge of vertigo,” he writes. “Instinctively I tightened my grip on the handrail … seeing an entire continent 400km beneath my feet caught me by surprise.”
6. You still have to do the vacuuming in space
Peake admits he spent his weekends in space doing the vacuuming. “A lot of dust collects in the return air filters of the ISS and it takes a couple of hours for the crew to vacuum them clean,” he recalls. The vacuum used was a standard commercial model - with an extra-long power cord.
7. Caving is perfect preparation for astronauts
A surprising component of Peake’s astronaut training was a seven-day caving expedition to Sardinia, Italy, where he and five other astronauts wriggled through confined spaces while collecting microbiological samples. The expedition helped to simulate the stresses he would experience on the ISS and promote the critical value of teamwork.
8. You can cycle in microgravity
Exercise was an essential part of Peake’s routine on the ISS, where the lack of gravity can reduce muscle mass and cardiovascular fitness. The ISS gym features the Advanced Resistive Exercise Device (ARED), a weight-training machine which uses piston-driven vacuum cylinders to enable astronauts to perform squat thrusts, bench presses and bicep curls.
One advantage of microgravity is that the ISS’s bike machine (called CEVIS) doesn’t even need a seat. “Instead, astronauts clip their bike shoes into the pedals, hold onto the handrails to stabilise themselves and pedal away,” notes Peake.
9. Going to the toilet in space is easier than you think
From classrooms to boardrooms, the most popular question Tim Peake gets asked is how astronauts go to the toilet in space. At the ISS, the toilets are about the size of a telephone booth. Both male and female astronauts urinate into a funnel attached to a hose which uses air flow to suck the liquid away. “Once you have suction going into the hose, it’s simply a case of maintaining good aim,” insists Peake.
When dropping their payload, astronauts use a small toilet fitted with foot restraints. The opening of the toilet contains a rubberised bag filled with hundreds of tiny perforations which are big enough to allow air to flow through (producing the suction required to remove the waste) but small enough to ensure no solids fall through. Astronauts then drop the bag into the solid waste container.
Urine is recycled on the ISS for drinking water but solid waste is loaded onto a resupply spacecraft that undocks at the end of the mission and burns up in the Earth’s atmosphere. “Think about that, next time you wish upon a shooting star,” warns Peake.
10. The journey home is a thrill a minute
When Peake returned to Earth in a Soyuz spacecraft in June 2016, it took just three and a half hours to travel from the ISS to the landing site in Kazakhstan – faster than a commercial flight from London to Moscow. Although the internal temperature of the spacecraft is regulated, when it enters the Earth’s atmosphere it can experience external temperatures of 1600 degrees. Peake likens the landing to “a minor car crash” but insists journeying home at speeds of up to 27,000kph is “the most thrilling ride of your life.”
Ask an Astronaut by Tim Peake (Century) is out now, priced £20.