Italian Paolo Nespoli, 54, has spent 174 days in space across two missions, travelling into Earth orbit on both NASA’s Space Shuttle and the Russian Soyuz spacecraft. We asked what it’s like to live in space, how it felt to witness the Space Shuttle docked to the ISS and more in our exclusive interview.

How It Works: Why did you decide to become an astronaut?

Paolo Nespoli: Ever since I was a little boy I wanted to become an astronaut. I was inspired by the Apollo missions, though not really Apollo 11. I was more interested in the later missions where they drove the rovers on the moon. I thought it was fascinating, with the astronauts jumping and driving around on the surface. Life was kind of different after that. I was drafted into the Italian army (they still had the draft back then) then figured out that I could make it as an astronaut. I applied twice to the European Space Agency (ESA) and didn’t make it, but on the third selection I made the cut.

HIW: Your first mission to space was on board STS-120. What was it like going to space for the first time?

PN: I was selected fairly young and got to fly after just nine years of training, which is somewhat of a short time to wait compared to many. People asked if I was scared but I wasn’t really. I’d trained so much, I knew what to expect. Feeling the acceleration in the Space Shuttle was amazing. The first couple of minutes it really shakes you. However, I was scared in space, because we’d trained for years and we only had 15 days to complete our mission. All I kept thinking to myself was, ‘You better not mess this up. People have been working on this for years!’ The fear of failure was the scariest thing about going into space.

HIW: What was the hardest part of going to space?

PN: I didn’t mind it so much in space, but my body felt really old when I came back to Earth; the gravity was so intense. I was fine in space, but I’m not exceptional or a superhero. Of the seven Shuttle crew members and three on the Soyuz I was the worst coming back by far. The micro-gravity environment does a lot to your body. You lose a lot of calcium in space; your bones and muscles can get quite weak.

HIW: How did you ensure your body stayed in shape? How did you adapt to life in space?

PN: We’d do about two hours of physical fitness every day. I would say you come back in better shape [in terms of fitness]. Doing two hours of exercise every day for six months, I came back with more muscles and less fat than when I left.

We did about one hour of cardiovascular exercise on a treadmill and another hour of resistance exercise. Obviously, you can’t lift weights in space, so a machine simulates the strain of lifting as on Earth.

There’s no training to prepare your body for its loss of balance. You get nausea and all sorts of things. Your skeleton also stretches (I was five or six centimetres taller than on Earth), and so muscles keep their strength but they are of a different length. Your body’s equilibrium shifts, and when you come back to Earth the muscles start contracting again, but they cannot find the equilibrium point so easily. I remember shaking constantly. Also I could be sitting and feel totally tired. Coming back to Earth is definitely the hardest aspect of being in space – for me, anyway!

On the station, you are isolated and confined, with only a few other people to talk to. You can’t just go out in the evening and see people. For some reason I discovered that whatever I was doing I was seeing pizzas all over the place, such as in clouds when looking at Earth. Freud would probably have a lot to say about that! I thought the food on the station was decent but far away from what an Italian would say is delicious. It was very good from a nutritional point of view, but a little horrific for an Italian. Maybe I was craving pizza because of food like that, or maybe I was just associating pizza with going out with friends and having a beer, maybe that is what I was missing. You are in isolation up there, and there are a lot of things you can’t do, a lot of things which aren’t normal.

Sometimes you forget that you’re in space. It takes about a month and a half before you get out of your ‘Earth habits’, getting used to space, doing things in a different way. For example, we had a table in one of the nodes for eating in the evening. That table had been there for years. It was horizontal in respect to the floor of the deck, because that’s how a table is on Earth. It was protruding a lot, and you’d often hit it when going past. One day I was looking at it and I thought, ‘There must be a way to do this better. Why is this table parallel to the deck, when there’s no gravity?’ You use Velcro to stick things to the table anyway so that they don’t float away, so why not have it at an angle, like a technical drawing table? I kind of tilted it up a little bit, then more, and more, until finally, if you look at it now, it’s tilted at a steep angle because you don’t need a horizontal table and it’s much more out of the way. It was there for ten years before somebody thought to move it!

I would say that it is an environment that is closed, isolated and confined. At first, when I was told I would spend six months on the station before the mission, I thought, ‘Oh my God, six months, are you out of your mind?’ Looking back I realised that I did not have the time to do everything I wanted, like taking more pictures, looking at Earth, playing around more, calling people, doing video clips. You end up doing things up there that make sense, time flies and everything is nice, but you wish you could have done more.

HIW: What was your favourite aspect of living in space?

PN: I loved taking pictures, looking at the Earth and [re]discovering it. It was very enjoyable. You just go to the window and there you have it – a great and gorgeous view. However, when you go to the window randomly, more often than not you’re just going to see an ocean with clouds. It’s nice and blue, but that’s about it. Sometimes you see a piece of land going by and it’s not so recognisable. It’s not easy to figure out what’s what, except Italy! When you start talking about the UK and Ireland it gets complicated because of the angle, cloud coverage, time of day and sun reflection, etc. In the beginning you try to figure out where you are without using the software that tells us, but little by little you start to know what’s going on. By the second/third/fourth months you look out the window and you know where you are – the continent, information, features that are there that you might want to take pictures of, or if it’s boring you might spend a few minutes on something else.

I started using more and more powerful lenses to capture some interesting details that I could see from up there. First I tried to see the Egyptian pyramids, the Great Wall of China, and other landmarks. I wanted to see an aircraft carrier at sea, some volcanoes, special islands, and then I started looking around randomly, taking pictures of things that were astonishing and different. I had this feeling that I was a scientist peering down a microscope that allowed me to take pictures of this small sphere rotating below, discovering microscopic things. I’d look at the pictures and realise that those things were 20 kilometres [12.4 miles] in diameter. You can’t really see things that are any smaller than that.

I became really interested in taking photos of landmarks and countries. I started using social media like Twitter and Flickr because I thought those things were interesting. I decided to start tweeting them to see what people thought. That turned out to be a pretty good source of enjoyment: finding something special and tweeting it to people, asking them for quizzes or riddles from space and seeing all the comments. It turned out to be a very enjoyable way to spend time, letting everybody participate in this adventure.

HIW: Were you asked to take the pictures by NASA or the ESA?

PN: I wasn’t asked to do it by NASA or the ESA. Some of the other astronauts had done it before me. I was not the first. Several of them told me that it was enjoyable. I did not tweet before I went into space because I don’t have much time to do it. I see some people go around with phones all day, typing what they are doing, clicking, clicking, clicking, but I have so many things to do. However, in space it worked out pretty well. Sometimes when I was taking pictures I was asking for help from ESA to identify what I was looking at. Other times I would guess but sometimes I would make a mistake, and people would correct me, so I learned that it was better to verify what I was seeing before half of the world thinks, ‘What is that stupid astronaut doing up there?!’ One of the first weeks I was up I tweeted a picture of a European city and really thought it was London… Turns out it was Paris. How can you make a mistake between London and Paris? It was beyond me. But in space, you travel so fast that you pass by so quickly, and you only have a few seconds to snap a picture. You have no time to research, so mistakes do happen.

HIW: Did it feel like you were travelling at 17,000mph?

PN: Well, it depends. If you are above an ocean, for example, which happened often, it doesn’t look like you are going very fast. But if you want to take a picture of something specific, then you understand how precise you need to be. I’m always on space time now. When I’m at home in the evening, and I look outside and see a sunset or moon. I see a nice picture and think, ‘Okay, I’m going to get my camera and I’ll take a picture in 30 minutes’. In space if you see the moon and you like it, you better take that picture in the next ten seconds because [otherwise] it’s gone. A good sunset is eight seconds and you think, ‘Oh, that’s a nice sunset, I’ll just get my camera… Holy cow, I need a picture now, where’s that camera!’ If you take out the card or wrong lens, then it’s gone. [This is how I mainly perceived speed on the ISS.]

You don’t feel anything physically on the ISS or the Soyuz capsule though. I remember when we detached from the station on Soyuz coming back to Earth, there is a moment in which the engine fires and you slow down and go into the atmosphere, and the capsule breaks up into three pieces. You are in the middle, the only one that gets to Earth; the others burn up in the atmosphere. At that point you are tumbling, finishing with a braking burn. The capsule has separated and you are waiting to be captured by the atmosphere. Then you look outside and realise you’re tumbling. It’s not a nice feeling. Are we supposed to be tumbling, you think. If you don’t look outside you don’t feel it, even at mach 25.

Naked

The only asteroid in the main belt visible to the naked eye is Vesta, which has a mean diameter of 530km and contains nine per cent of the entire asteroid belt’s mass.

Coma

The way comets and asteroids are distinguished relies on visual appearance, with comets displaying a perceptible coma behind them while asteroids have none.

Naming

Once an asteroid has been discovered it can only be named under the consultation of the International Astronomical Union, who will approve or disapprove the proposition.

Photo

The first true asteroids to be photographed close up were Gaspra in 1991 and Ida in 1993. They were imaged by the Galileo space probe en route to Jupiter.

New

The latest asteroid to be landed on is Itokawa, an S-type asteroid that crosses the path of Mars. The Hayabusa space probe returned to Earth with a surface sample.

The universe is a dangerous place. Black holes, gamma ray bursts and pulsars could all seriously damage or even destroy our planet if they were close enough, but the fact of the matter is that there is nothing in our vicinity that poses an immediate threat, at least for the next few billion years. The nearest star that could go supernova is Betelgeuse, 640 light years away. In fact this star could be about to go supernova in one minute, one year or a thousand years; all astronomers know is that it has reached its Chandrasekhar limit and it could blow at any second, when it will appear as one of the brightest stars (other than the Sun) in the night sky. But just how close would a star have to be to cause irreparable damage to Earth?

100 light years away

At this distance a supernova poses no threat to Earth. The intensity of a supernova’s energy dissipates exponentially, so other than observing a bright star in the night sky we would experience no effect on Earth. The closest star to Earth that could go supernova is Betelgeuse, 640 light years away, but it poses no threat to us.

50 light years away

In several billion years it is possible that a star closer to home will go supernova. If one did so about 50 light years from Earth, it is likely that it would shear the ozone off our planet, in turn also destroying the Earth’s magnetic field. This would make our world all but uninhabitable.

1 light year away

The closest star to Earth is the red dwarf Proxima Centauri just over four light years away, but there is no chance of it going supernova. Theoretically, though, if a star were to go supernova one light year away from Earth it would rip our planet and the entire solar system to shreds. The force of the shockwaves would easily destroy every nearby celestial object, and leave our solar system as a nebula remnant that would eventually lead to the formation of new stars and planets.

Unlike rocky planets such as Earth, the sun does not have a definitive outer boundary. However, the different layers beneath the Sun’s surface are defined by their temperatures and density. Although the core is on average the hottest part of the Sun, the complex relationship between rising heated gases and falling cooled gases create temperature fluctuations within the layers of the Sun itself.

(Image courtesy of NASA)

To date there have been 42 missions to Mars, with exactly half of them complete failures. Other than the Earth it is the most studied planet in the solar system, and for centuries it has been at the heart of wild speculation and groundbreaking scientific discoveries. Observations of Mars have not only revealed otherwise unknown secrets but also posed new and exciting questions, and it is for these reasons that it has become the most intriguing planetary body of our time. Take a look at the map above to see key geological points of interest as well as the landing and crash sites for several spacecraft.

This image of the surface of Mars was created by reconstructing data from NASA’s Mars Global Surveyor, the Mars Orbiter Laser Altimeter and observations by NASA’s Viking spacecraft.

Astronauts Jack Schmitt and Gene Cernan break into song during the Apollo 17 mission of December 1972.

9. Bunny hopping on the moon

Gene Cernan discovers a new and easier way to get around on the Moon during the Apollo 17 mission by jumping with two feet rather than more traditional walking methods.

8. Alan Shepard plays golf

Becoming the first and only person to play golf on the Moon, Alan Shepard takes a couple of shots during the Apollo 14 mission.

7. Armstrong and Aldrin unveil lunar plaque

Neil Armstrong and Edwin “Buzz” Aldrin unveil a plaque left behind on the Apollo 11 mission, which finishes by stating: “We came in peace for all mankind.”

6. Hammer throw

Astronaut Jack Schmitt throws his geology hammer into the distance before Apollo 17 takes off after pleading for permission.

5. Galileo proved corrrect

During the Apollo 15 mission, commander David Scott drops a hammer and feather simultaneously to show that, in a vacuum, all objects fall at the same speed with an absence of air resistance, proving Galileo’s hypothesis.

4. Astronaut takes a tumble

Proving just how difficult it is to cope with the Moon’s weak gravity whilst wearing top-heavy space suits, Jack Schmitt has a couple of falls during the Apollo 17 mission before being called “twinkletoes” by mission control.

3. On board a lunar rover

Astronaut John Young takes the lunar rover out for a spin on the surface of the Moon during the Apollo 16 mission of April 1972. Although only designed to reach about 8mph (13kph), Young unofficially holds the Lunar Land Speed Record of 11mph (18kph).

2. First man on the Moon

Neil Armstrong becomes the first human to set foot on another celestial body at 0256 GMT on 21 July 1969. Many people believe that he fluffed his famous lines as he stepped on to the surface, missing out the “a” as he proclaimed it was “one small step for [a] man, one giant leap for mankind.” However, listen closely and you can almost make out an “a” just after he said “for”, and Armstrong later insisted that he did say “a man”. What do you think?

1. Last humans on the Moon

Marking the end of NASA’s missions to the Moon, the ascent stage of Apollo 17′s Lunar Module takes off on 14 December 1972. On board were Harrison “Jack” Schmitt and Eugene “Gene” Cernan, the last humans to set foot on the Moon. The footage was taken by a camera on the lunar rover left behind on the surface, tracked manually by mission control on Earth.

Rockets like Saturn V, the one used to launch NASA’s Apollo and Skylab programs, are multi-stage liquid-fuelled boosters. The Saturn V is considered to be the biggest, most powerful and most successful rocket ever built.

The Saturn V was 110.6m tall, 10.1m in diameter and had a payload of 119,000kgs to low-Earth orbit.

There were three stages, followed by an instrument unit and the payload (spacecraft). The total mission time for this rocket was about 20 mins. The centre engine was ignited first, then engines on either side ignited. The first stage lifted the rocket to about 70m and burned for 2.5 mins.

When sensors in the tanks sensed that the propellant was low, motors detached the first stage. The second stage continued the trajectory to 176km and burned for six mins. About halfway through this stage’s ignition, the instrument unit took control of calculating the trajectory.

Second stage complete, solid-fuel rockets fired it away from the third stage. The third stage burned for 2.5 mins and stayed attached to the spacecraft while it orbited the Earth, at an altitude of 191.2km.

It continued to thrust and vent hydrogen before ramping up and burning for six more minutes, so the spacecraft could reach a high enough velocity to escape Earth’s gravity.

5. Phobos-Grunt

This 14.5-ton Russian spacecraft, which also carried China’s first attempt at a Mars orbiter, was intended to retrieve soil samples from the Martian moon Phobos (‘grunt’ means ‘soil’ in Russian). Unfortunately, it experienced a failure immediately after launching in early November 2011 and became stuck in Earth orbit. It crashed into the Pacific Ocean on 15 January 2012.

4. Compton Gamma Ray Observatory

The 17-ton Compton Gamma Ray Obsevatory (CGRO) was the second of NASA’s “Great Observatories”, following the launch of the Hubble Space Telescope in 1990. It was launched on 5 April 1991, but experienced a gyroscope failure nine years later. It did not possess the capability to be repaired in orbit like Hubble and thus NASA carried out a controlled re-entry on 4 June 2000, the first it had ever attempted.

3. Salyut 7

On 7 February 1991 the Soviet space station Salyut 7 came back into Earth’s atmosphere in an uncontrolled re-entry after spending nearly nine years in space. At the time of the re-entry a spaceship called Cosmos 1686 was docked to the station, giving a combined weight of 44 tons. The station had been unmanned since 1986 following a series of technical problems, including a power failure that had caused ice to form on the space station’s interior walls. It re-entered over Argentina on 7 February 1991, scattering debris over the town of Capitan Bermudez.

2. Skylab

NASA’s first space station, Skylab, weighed 69 tons. It was launched on 14 May 1973 and completed a variety of Earth observations, but in early 1979 NASA discovered that the station was falling into a lower orbit. Amid a huge media storm Skylab re-entered Earth on 11 July 1979. The majority of the spacecraft burnt up in the atmosphere but parts of it fell in Western Australia. Read more about Skylab’s demise here.

1. Mir

The largest man-made object to ever fall back to Earth was Russia’s Mir space station. Weighing a hefty 135-tons, this giant space station was de-orbited by engineers in 2001. Its re-entry was controlled to ensure that the majority of the space station burnt up in the atmosphere and the remainder crashed into the Pacific Ocean. The station had remained operational since its launch on 20 February 1986, setting a number of records along the way including the longest stay by a human in space (Valeri Polyakov, 437.7 days).

No one knows for sure, but we can make estimates based on the expected age of the universe and the motions of galaxies throughout the universe. The universe itself is expanding, but not in the way a balloon expands. The expansion is taking place throughout the universe, where space-time itself is being stretched outwards. Whereas a balloon pushes its edges out as it expands, the universe is also pushing its insides outwards as well, but there is no centre of the universe, so everything is moving away from everything else. It’s a bit like baking a ball of dough; the entire dough expands and grows, not just its edges.

However, based on our knowledge of how old the universe is, roughly 14 billion years, we can observe a theoretical ‘edge’ of the visible universe about 14 billion light years away from us. This is the furthest distance we can see, as light that might be further away has not had time to reach us yet. Thus, we can say that the visible universe has a diameter of 28 billion light years, 14 billion light years in either direction from Earth. However, what’s beyond this distance is unknown. The 28 billion diameter visible universe we can observe could be just a tiny fraction of a much larger universe, or perhaps just one in a system of many universes.

To learn more about mega rockets pick up issue 29 of How It Works, on sale today.