Ask an Astronaut

Well, if you’re thinking of becoming an astronaut you have certainly picked the right time. Just as the Apollo missions in the 1960s took a giant leap for humankind, so we are now on the cusp of a new golden age of space exploration. In the coming decades we can expect to colonise the Moon, set foot on Mars and travel deeper into our solar system than ever before. These dreams of human endeavour are now within touching distance, and we can all be a part of this remarkable journey.

But answering this question is not straightforward, since there is no set path to becoming an astronaut. I was 43 years old when I arrived on board the International Space Station (ISS) on 15 December 2015. I felt enormously privileged to be there and to be following the same career path as men and women I had revered all my life. It was hard to believe I had been fortunate enough to join this exclusive band of spacefarers.

A total of 545 people from 37 different nations had reached Earth’s orbit before me, since Yuri Gagarin’s first intrepid launch on 12 April 1961. As a small cadre of space explorers, we hail from a wide range of careers and backgrounds – school teachers, pilots, engineers, scientists and doctors – and from every corner of the globe. The one thing we all share is a love of exploration and a passion for human spaceflight.

Of course there are certain skills and characteristics that you need to possess as an astronaut, or acquire during training, and the right stuff for today’s astronauts is not exactly the same as it was in 1960. Some of these attributes may surprise you – being good at languages, for instance, is extremely useful. Equally important is what you do before you become an astronaut. It’s key to find a career that you’re passionate about, and to be as good as you can be in that field. It’s good to have an education in science, engineering, technology, mathematics or medicine, but academic qualifications only get you so far. It is your drive, your enthusiasm and, above all, your personality and character that will enable you to succeed.

Shortly after landing back on Earth I was asked in a press conference if I had a message for the children from my old school. My own journey had begun in a small village outside Chichester, on the south coast of England. It had taken nearly 18 years in the Army and a career as a test pilot to put me in the right place at the right time to become an astronaut. I replied, ‘You’re looking at a boy who went to Westbourne Primary School, who left school at the age of eighteen with three average A-levels, and I’ve just got back from a six-month mission to space, so my message is: don’t let anybody tell you that you can’t do anything you set your heart on.’

Make no mistake, becoming an astronaut is not easy. In fact it has been the single hardest thing I’ve ever done. But it has also been the most rewarding pursuit by far – full of tremendous experiences that I will treasure for the rest of my life.

15 December 2015, Kazakhstan. 14.33 local time. Launch minus 2 hours, 30 minutes.

I was standing 50 metres above the launch site, at the top of the glistening Soyuz rocket, waiting to climb inside. It was a gloriously clear winter’s day. Looking out over the sprawling Baikonur Cosmodrome and the vast expanse of grassland that was the Kazakh Steppe, my senses were in overdrive absorbing the last sights, smells and sounds of planet Earth before I left for six months.

As I climbed aboard our tiny capsule, situated within the nose-fairing of the rocket, the vehicle felt completely alive beneath me. Cryogenic fuel was continuously boiling off, covering the base of the rocket in an eerie white fog. This sub-zero propellant caused a layer of thin ice to cover the lower two-thirds of the rocket, transforming the usual orange-and-green livery of the Soyuz into a dazzling white in the afternoon sunshine. We had enjoyed a close-up view of the rocket as we took the lift-ride up to our capsule. With it fully fuelled with 300 tonnes of liquid oxygen and kerosene, hissing and steaming within its metal support structure that held it in place prior to ignition, you get a real sense of the incredible engineering it takes to escape the force of Earth’s gravity. I’ve strapped into many aircraft in my career, but I’m certain nothing will ever come close to the exhilaration of climbing aboard a rocket prior to launch. I didn’t feel nervous; quite the opposite. I had waited a long time for this moment and, despite trying to maintain a calm, professional focus, I was only too aware of a boyish excitement building deep within me.

We always climb into the capsule in a specific order. The first one in is the left-seater (Tim Kopra in our case), then the right-seater (myself), then finally the Soyuz commander (Yuri Malenchenko). First, we had to enter the crammed habitation module through a horizontal hatch and then wiggle our way, feet first, down through a vertical hatch to enter the descent module. There’s no ladder, but there are footholds that help.

We had to be very careful squeezing past the vertical hatch as it contained the antenna, which would be needed six months later to transmit our location to the search-and-rescue crews after landing. It was a real squeeze getting into the seat. Unlike the Soyuz simulator back in Star City, Russia, where we had trained, the spacecraft was packed to full capacity with cargo. Initially I dropped down into the commander’s seat and then cautiously shifted across, feet first, into my right-hand seat. Everything had to be done very slowly and carefully. This was not the time to tear my spacesuit or cause damage to the spacecraft. I thought of all the times I’d been caving, during my training, and was grateful for having had some experience of working in extremely confined spaces.

As soon as I was in my seat, there were two electrical cables and two hoses that had to be connected to the Sokol spacesuit. The electrical cables were for my communications headset and medical harness, which I had donned earlier. All crew wear a medical harness next to their chest, which measures heart rate and breathing rate, with the data being transmitted back to our flight surgeons. The two hoses were for air (for cooling and ventilation) and 100 per cent oxygen (used only in the case of an emergency depressurisation). Having made these connections, the next steps were to connect my knee braces, which would prevent injury to my legs during any high g-loading that might occur during launch, and to secure my five-point harness. There was just enough room for one ground-crew member to help me strap in and hand me my checklists.

As I counted the minutes until launch, meticulously reviewing the checklist one last time and mentally visualising the crucial minutes and hours ahead, there was time for one final tradition to be observed, to get the adrenaline flowing. Each cosmonaut is allowed three songs to be piped into the capsule before lift-off. I had elected for ‘Don’t Stop Me Now’ by Queen, ‘Beautiful Day’ by U2 and ‘A Sky Full of Stars’ by Coldplay. As the crew’s chosen compilation faded, and with only moments to go until ignition, there was one last surprise. Through our headsets, and drowning out the loud burr of the rocket, we heard the familiar synthesiser notes and guitar chords of ‘The Final Countdown’ by Europe, chosen by our Soyuz instructor – who says the Russians don’t have a sense of humour!

During our fully automated docking sequence there was a problem. We were approaching from below the space station, docking to a Russian module called Rassvet. I was struck by the sheer size of the ISS as the Soyuz crept slowly inside the enormous solar panels – I remember commenting to Tim Kopra on the size of those solar panels, forgetting that at this stage everything we said was being transmitted back to Mission Control… rookie error! As we edged nearer the space station, I was surprised to see quite how close the Cygnus resupply spacecraft looked; it was docked just forward of our docking port and appeared large outside my right-seat window. Cygnus had two large umbrella-shaped solar panels protruding on either side at the base of the vehicle, and it seemed there would be only a metre or so of clearance as our Soyuz nudged closer.

Everything was progressing normally until, at just 17 metres away from the ISS, one of our thruster pressure-sensors failed, forcing the Soyuz to command an automatic abort and sending us back out into space. Yuri, our very experienced Russian Soyuz commander, was in the centre seat and on his sixth mission to space. He quickly took manual control of the spacecraft. Using two hand-controllers, he had to realign the spacecraft and fly it back in to dock with the space station. However, we were about to transition from day to night, with only three minutes remaining until we entered the shadow of Earth. The Sun was very low and reflecting off the space station towards the Soyuz, which made it almost impossible for Yuri to see Rassvet’s docking target clearly.

During Yuri’s first docking attempt, as the Soyuz approached the ISS, it drifted towards the aft end of the space station and yawed off-target. Docking is one of the most critical phases of spaceflight. A collision between vehicles can not only cause irreparable damage, potentially leaving a spacecraft stranded with no power or control, but it can also rupture the hull, causing a rapid depressurisation and placing the crew’s lives in jeopardy. Such a situation occurred on 25 June 1997 when a Progress resupply vehicle struck the Mir space station with near-disastrous consequences.

Thankfully, Yuri’s experience and hours of manual docking attempts in the simulator paid off. Recognising the danger, he backed away from the space station, realigned the spacecraft and manoeuvred the Soyuz back in, for a textbook docking. That was probably the moment of greatest apprehension for me, Tim and Yuri – getting that docking right and ensuring we arrived safely aboard the space station.

Fortunately there weren’t any other scary moments during the mission. Scary moments in space are never a good thing! However, some parts of spaceflight definitely have more potential for things to go wrong, and we would always focus our training on these ‘high-risk’ areas, as a means of mitigating the dangers. Unsurprisingly, the main areas that require greater attention to detail are launch, re-entry, spacewalking and docking operations (including visiting cargo vehicles).

This is a favourite question of mine and yet one of the hardest to answer. That’s because yes, space does smell… but exactly what it smells of is much harder to put your nose on.

I smelt space on a number of occasions. The first time was after just a few days on the Space Station, when I was helping astronauts Tim Kopra and Scott Kelly back in after their spacewalk. Subsequently there was a strong and distinctive smell whenever we opened the airlock after it had been exposed to the vacuum of space. I noticed the same odour each time I used the Japanese airlock, when transferring small satellites through it for launch or recovering experiments that had been outside the space station for several months.

The mystery scent is the topic of much light-hearted debate among astronauts. It has been described as seared steak, hot metal, welding fumes and barbecues, to name but a few. There are some suggestions that the smell may originate from the spacesuit itself, with certain components ‘off-gassing’, having been exposed to vacuum and thermal extremes. However, I smelt the exact same smell a couple of times inside an empty Japanese airlock following re-pressurisation. In my opinion, the smell of space is like static electricity. For example, when you take off a shirt or jumper and sometimes get a large static discharge – it has that kind of burnt metallic smell.

Actually what you’re most likely smelling with static electricity is ozone. Ozone can occur naturally when high-energy ultraviolet rays (from the Sun, lightning or static electricity) strike oxygen molecules, splitting the molecule into two single oxygen atoms. A freed oxygen atom then combines with another oxygen molecule to form O3 – ozone. Although ozone is present in the lower part of the stratosphere at around 20–30 km above Earth, it is not present at 400 km, so why would we smell it in space? Well, atomic oxygen is present in space. In fact, between 160 and 560 km, what little atmosphere there is consists of about 90 per cent atomic oxygen. It’s possible that atomic oxygen is being introduced to the airlock when it is exposed to space, and on re-pressurisation it’s reacting with oxygen molecules from the space station atmosphere, thereby creating ozone.

Perhaps the most wistful theory is that the smell of space is the leftover aroma of dying stars. There’s an awful lot of combustion going on in the universe. Stars mostly comprise hydrogen and helium gas, powered by a nuclear-fusion reaction that can last for billions of years. At the end of its life, as the hydrogen fuel is used up, a star will collapse on itself and undergo a violent supernova explosion, during which heavier elements such as oxygen, carbon, gold and uranium will be produced. All this rampant combustion produces smelly compounds called ‘polycyclic aromatic hydrocarbons’. These molecules are thought to pervade the universe and float around for ever. So are we smelling the leftovers from some of the earliest stars, when we stick our nose into the airlock? Who knows.

Either way, I found it a rather pleasant smell and it reminded me a little of a British summer barbecue, burning sausages on a charcoal grill.

It’s a common misconception that there is no gravity in space. In fact, gravity is everywhere! The great Sir Isaac Newton published his law of universal gravitation in 1687, supposedly after a close encounter with an apple. Newton described gravity as a force, stating that a particle attracts every other particle in the universe with a force that is directly proportional to the product of their masses, and inversely proportional to the square of the distance between them. This means that the force of attraction between two objects reduces (rather rapidly) the farther apart they are, but it never completely disappears. In this sense, gravity is the force that connects all matter in the universe.

Forces are nice, easy things to comprehend and we can understand the pull of the Sun that keeps the planets in their orbits, or the pull of Earth on the Moon. However, in 1916 another genius, Albert Einstein, complicated matters somewhat when he published his theory of general relativity. This had big implications for gravity. In essence, we now understand gravity not as a force, but rather as the curvature of space-time. Matter causes space-time to bend, warping the shape of the universe. Gravity is the effect that particles feel as they travel through this curved space-time on their journey through the universe. Newton’s law still remains an excellent approximation of the effects of gravity in most cases, but when there is a need for extreme precision, or when dealing with very strong gravitational fields, then Einstein’s relativity is required.

So you cannot travel through space without feeling the effects of gravity everywhere. On the International Space Station we are most definitely being affected by Earth’s gravity, just as we are by the Sun’s, by that of the other planets in the Solar System and the supermassive black hole at the centre of the Milky Way (called Sagittarius A). Even as you read this book, the mass of your body is causing a small amount of curvature in space-time, which will be having an effect on the orbit of the ISS (admittedly, this is a rather small effect!).

The story of gravity is far from complete. Einstein’s theory of general relativity has so far stood the test of time, and now scientists are in search of things like gravitational waves and gravitons, and are musing on the concept of gravity propagating through the universe at the speed of light. However, we still don’t really know what gravity is; we only know how it behaves.

Ha, what a great question! By far the grossest thing about living in space is watching the soles of your feet disintegrate during the first couple of months in space. We hardly use the soles of our feet on the space station, and there is seldom any weight on them (except when we exercise). Because of this, they become very smooth and soft, like a newborn baby’s. Six months in space is akin to having the best pedicure you could imagine.

The gross part is that all the dead, hard skin that builds up on the soles of your feet starts coming off. After living in space for a few weeks you have to take your socks off very carefully, otherwise there will be a shower of dead skin-flakes ejected into the cabin. As nothing sinks to the floor in microgravity, this skin would just hang around until the airflow gradually pulled it towards one of the return air filters. Meanwhile you would rapidly become the least popular member of the crew!

Equally gross is the fact that we develop ‘lizard feet’ on the tops of our toes. We are constantly hooking our feet underneath metal handrails, straps and bungees and using this force to hold us down and stabilise our body position whilst we work. All of this abrasion causes the skin on the tops of our toes to become very rough and scaly. In fact the European Space Agency has even experimented with specially designed socks, in an effort to prevent this. The socks have a soft rubber coating over the top of the toes and do help, to some degree.

This is by far the most popular question I get from younger children. Okay – here it is! Going to the loo in space is not so different from doing your business on Earth, but there are a few important things to remember. First, we do enjoy some privacy, since the loo is screened off in an area about the size of a telephone booth. Inside, there are some foot restraints that we use to keep ourselves stable (the fewer things floating around, the better). We pee into a hose that has a conical-shaped receptacle with a switch on the side. The most important thing to remember is to first turn the switch, which operates a fan. The whole concept of the space-loo is that, in weightlessness, airflow is your friend and keeps everything moving in the right direction. Once you have suction going into the hose, it’s simply a case of maintaining good aim or, as I tell my two young boys at home, don’t be a secret splasher! Female astronauts use a different (oval-shaped) urine receptacle, but otherwise the principle is the same.

For No. 2 there is a rather petite loo seat secured on top of a solid-waste container. This container has a small circular opening, around which is stretched a rubberised bag with an elasticated opening. Hundreds of tiny perforations in the bag allow air to flow through it, but not solid waste. The same switch on the urine hose activates airflow through the solid-waste container. On successful completion of business, astronauts drop the (self-sealing) rubberised bag with its contents into the container and leave a fresh bag in place for the next crew member. The solid-waste container is changed about every 10 to 15 days, although one ISS commander proudly told me that if you put on a sterile glove and pack down the contents, you can stretch this out to 20 days. I’m not sure the space programme fully appreciates the levels we go to, to conserve resources!

Air that is sucked through the loo is then dried, filtered and deodorised, prior to being returned to the living quarters. There are two toilets in the space station – one in the Zvezda module of the Russian segment and one in Node 3 of the US segment. Despite being a fairly uncomplicated procedure, use of the space-station loo has not been without incident. One astronaut (who shall remain nameless) told me that following a call of duty one day, he turned around to dispose of the rubberised bag into the solid-waste container, only to find the bag completely empty. Feeling quite certain that it was supposed to contain a decent-sized portion of metabolic waste, there followed a fervent search for the liberated object. As with most missing items in space, it vanished into thin air until two weeks later when, during routine maintenance on the loo, another crew member made a remarkable discovery of a small, hard and dried-up foreign body wedged into a small gap near the return air filter!

When Tim Kopra and I egressed the airlock on 15 January 2016, our main objective was to replace a failed Sequential Shunt Unit, or SSU, located at the base of one of the solar panels on the farthest starboard edge of the space station. The SSU receives coarse voltage from the solar panel and regulates it, so that the solar array operates at a constant voltage and load. With the SSU failed, the space station was down one-eighth of its electrical power, so it was an important job to restore the space station to full capability.

Tim and I had to get to the worksite in a safe, yet expeditious, manner. Timing was critical to this EVA. Since the SSU receives coarse voltage from the solar panel, there is no way of switching it off. The only way to change it out safely is to wait until the Sun goes down . . . no Sun = no solar-power generation. Our timings were based on being in position at the worksite and ready to change out the unit just before sunset. As it happened, Tim and I made good progress and we were in position ten minutes ahead of schedule. Rather than putting us to work on another task and risk something detracting from our main objective, Mission Control elected to have us wait in position until darkness. Being told to ‘hang out’ for ten minutes on a spacewalk and watch a sunset, whilst floating at the very edge of the space station, is unheard of. Having grabbed the opportunity to take some photos (including the obligatory spacewalk ‘selfie’), I had about five minutes to soak up the view and reflect on my situation.

During my spacewalk by far the best part was a feeling of awe and reverence during those precious few minutes of ‘hanging out’ in space. As we crossed the terminator from day into night, it was like having a front-row seat in nature’s own IMAX theatre. I had a similar feeling when I first looked out of the Cupola window, although spacewalking took this to another order of magnitude. I had the ability and freedom to turn in any direction, one minute marvelling at how fragile and beautiful Earth looked as it slipped gracefully into shadow, the next minute being intimidated by the vast blackness of space stretching into infinity. It certainly gave new meaning to the word ‘perspective’. Unencumbered by the effects of gravity, not feeling the weight of my spacesuit or noticing the thin visor in front of my eyes, I felt completely detached – utterly removed from Earth, civilisation, the space station. I had the sensation of being a microscopic spectator in an immeasurably vast universe. It was, at the same time, the most astonishing and humbling experience of my life.

Falling off the space station is most astronauts’ worst nightmare. In the opening scenes of the 2013 movie Gravity, Sandra Bullock’s character finds herself detached from the Space Shuttle, tumbling uncontrollably through space, left to the mercy of the laws of physics. Under these circumstances, an astronaut would eventually die, most likely asphyxiated after several hours, as the spacesuit’s ability to scrub carbon dioxide from the atmosphere slowly failed or the battery power ran out. It is no surprise, then, that we go to extraordinary lengths to ensure that astronauts do not go tumbling off into space to suffer a lingering death.

It’s actually surprisingly easy to fall off the space station. The spacesuit gloves that we wear are bulky and cumbersome. The palms are coated with a special rubber material that gives adequate grip, but the gloves’ thickness does not allow much fidelity or ‘feel’. It’s difficult to know how hard you need to grip something. To begin with, most astronauts end up holding on too tight, but with practice you learn to relax your grip and think like a rock-climber. The outside of the space station is covered with handrails and other structures that we can hold on to. However, there are also plenty of places that are dangerous to touch, either because they are sharp and could cut open a glove or because we might cause damage to the space station. So the first line of defence against falling off boils down to good planning, preparation and training: know where you are going.

I studied for hours the routes that I would follow during my spacewalk, analysing the reach between each hand-hold, the best body positions needed to span difficult gaps and planning alternative routes, in case things didn’t work out. In addition to memorising planned routes and worksites, you also need to be able to think on your feet, in case there’s a requirement to work in an area you’ve not prepared for. Hours of underwater training for spacewalks give you the skills and confidence needed for this.

The second line of defence is a mantra drilled into all rookie astronauts: ‘You stop, you drop’ – meaning that whenever you stop moving, the first thing you do is attach yourself to the space station using a short ‘local’ tether (about 1 metre long). Astronauts often have to let go of the space station with both hands, in order to use tools and equipment, work on a task, and so on. If you allowed yourself to become distracted, it would be all too easy to forget to first attach your local tether, and then let go and drift off into space.

Our third line of defence is a safety tether. This is like an oversized fishing reel, with one end anchored to the space station and the other end attached to our spacesuit, dispensing a thin steel wire on a spring-loaded retractable reel wherever we go (it was the small tug from this reel that allowed Luca to find his way back to the airlock, when his helmet filled with water during a spacewalk). However, this thin steel wire is a double-edged sword, and astronauts must remain constantly vigilant not to get tangled up in their own or their crewmate’s safety tether. When planning a spacewalk, astronauts take special care to try and use separate routes or to think of a strategy that avoids potential entanglement.

Finally, if all else fails, our spacesuits have a built-in jet-pack, called SAFER. But as much fun as it sounds to go scooting around space with a jet-pack, I don’t know of any astronaut who would relish the thought of having to use this last line of defence.

I love this question – it makes me think of opening up a small market stall on the ISS selling postcards, trinkets and souvenirs. The trouble with the space station is that most of the stuff that would make great souvenirs is usually quite important, and the space agencies would get really upset if astronauts started stripping the place. After all, it costs a lot of money to fly things to space and so, once up there, they probably ought to stay there. Having said that, I did get to keep a few items that are very special to me.

I was able to bring back my space cutlery, which is really cool as it is engraved with ‘Shuttle’. I guess we’re still using up old stock and haven’t yet opened the box containing the cutlery engraved ‘ISS’! I also have a crushed Russian coin that I had in my pocket. That may sound a bit odd, but another Russian superstition is that it is good luck to carry a coin crushed by the train that pulls your rocket to the launch pad. I had asked one of my Russian friends if he could lay a coin on the railway track the morning that our Soyuz rocket ‘rolled out’ to the launch pad, as we were confined to quarantine at the time and it is considered bad luck for the crew to attend the roll-out ceremony.

However, the most special souvenir I was able to bring back was the Union Flag that I wore on my spacesuit during my spacewalk. As the first Union Flag to be worn in the vacuum of space, it holds a special significance, and to me it represents a new chapter in the UK’s long and distinguished history of exploration and scientific research. I was fortunate to see a magnificent exhibition from the Royal Archives and the Royal Collection a few years before my mission, displaying artefacts from British exploration throughout history. I could think of no better place for this well-travelled flag to reside, and since returning from space I have had the honour of presenting this Union Flag to Her Majesty Queen Elizabeth II.