WHEN I WAS a boy of ten I was taken along to the local astronomy society by my father and on that cold frosty January night almost thirty years ago I saw something that changed my life. As I took my very first peek through a telescope I was greeted by a view of the mighty Saturn, hanging in the inky black depths of space. I could see the delicate hues of the belts on the planet, the rings encircling it, and a moon or two as well. It was an incredible sight, and to this day I have never seen another view that has left quite such an impression on me. During that short encounter it felt as though I had been transformed into an astronaut and was in orbit around an alien world. It was magical. My childhood following that experience was often filled with boyish dreams of becoming a spaceman, and I spent much of my youth working on projects that I hoped would help to fulfil my ambition of flying around the Solar System, taking in strange new worlds and distant moons. But I was not alone. As I was making cardboard rockets, tinfoil space suits and papier-mâché helmets, millions of other children were at home doing the exact same thing.
Dreams of becoming an astronaut have been common among children ever since 20/21 July 1969, when families the world over were huddled around their television sets watching Neil Armstrong and Edwin ‘Buzz’ Aldrin land on the Moon and become the first men to walk on its surface. Millions were transfixed by the hazy, flickering footage being beamed live from over a quarter of a million kilometres away. Watching those brave explorers, the first humans to set foot on extraterrestrial soil, excited children; they wanted to be those men, to journey into the unknown and explore different worlds. Suddenly space travel was not just the stuff of science fiction but a reality, something tangible and achievable. Even now, decades later, the story of Armstrong, Aldrin and Mike Collins, who stayed in the command module of Apollo 11, continues to inspire countless children who dream of reaching out to the stars.
And these dreams of space exploration aren’t just confined to youngsters. As we grow up we may loosen our grip on the desire to become astronauts, but there are plenty of other ways through which we channel our deep-rooted fascination with the alien and the unknown. There are examples scattered through history; poets, authors, artists and musicians have produced many works based on the Universe around us. You only have to think of the beautiful orchestral pieces by Gustav Holst inspired by the planets or the plethora of science fiction stories and films to see that astronomy reaches out to people in a way no other science does. We have always been fascinated by the unfamiliar, largely because it allows our imagination free rein to conjure up all sorts of weird and wonderful fantasies. Alien worlds and their potential inhabitants are the epitome of this, and the dream of space exploration has been a part of human culture for many years. Be it through fear or fascination, it has also proved to be a unique way of bringing people together, as the photographs from NASA’s Apollo era demonstrated. Not only did the images give us a new view of the Moon, they also gave us a fresh perspective on Earth. Who can fail to be humbled after seeing pictures of our fragile planet hanging in the dark, cold, lonely depths of space?
Out of my childhood dreams and games grew an interest in astronomy and the Universe that has followed me into adulthood, along with questions and ideas that have been bubbling around in my head for many years. I have always wanted to see my home, planet Earth, from space and to learn more about its relentless orbital dance with the Moon. I dream of heading to Mercury and Venus, and to the Sun to learn how it works and see just how close it is possible to get to those incredible temperatures. I want to know if it is possible to survive one of the sandstorms on Mars, or to navigate through the dense rocks of the asteroid belt as I approach the realm of the gas giants. Would it be possible for me to fly through the eye of Jupiter’s Earth-smashing hurricane, which I have seen through a telescope on many occasions, and are the rings of Saturn really made up of billions of pieces of rock and dust?
Approaching these questions from a theoretical perspective, I often give lectures to others like me who are in awe of the Universe. Children are regularly in the audience and it never ceases to amaze me how wonderfully insightful their questions can be. I recall a child of about ten years once asking me, ‘What shape is the Universe?’ That’s a fantastic question to come from an adult, and I was surprised to hear a child ask it. It just shows that we all have probing thoughts and unanswered queries about worlds beyond our own. In some ways, I think the wonderment of children is analogous to that of our ancestors as they slowly became aware of the Universe around them. Sadly, I think a lot of adults tend to lose this fascination with the natural world; but that one question made me realize that trying to understand the secrets of space brings us all together. Certainly everyone else in the room with that ten-year-old boy was waiting for my answer. Whatever your age, we are all on this journey of learning and discovery together.
You may be surprised to know just how much we have come to learn about the Universe from remote observation. Indeed it is fair to say that we have learned more by study through a telescope than we have by direct exploration. But there are limitations, and these are largely a result of our technological capabilities. As technology develops and we discover new ways of exploring the Universe, both by remote observation and direct exploration, our view of the Solar System and the planets will change and evolve. But before you climb aboard your spacecraft it is worth glancing back briefly at the past, to take in some of the important discoveries that have led to our current view of the Solar System.
By ‘Solar System’, I mean the region of space that is dominated by the influence of the Sun. It includes the planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune and a whole host of comets, asteroids and minor planets. Our distant ancestors knew that these bodies were different to the stars around them because they could see them moving independently. Indeed the term ‘planets’ comes from the Greek word planes, which literally means ‘wanderer’, and that nicely describes how they seem to move aimlessly against the background of the stars. For many centuries it was believed that the Earth was at the centre of this system, with the Sun, Moon, planets and stars all in orbit around us. This model was known as the Geocentric Model and it was articulated in a piece of work by the Greco-Egyptian scholar Claudius Ptolemaeus, or Ptolemy. However, more detailed observations of the motions of the planets, for example the strange backward or retrograde loops of Mars, revealed that the Earth could not be at the centre of the Solar System. An alternative model was suggested as early as 3 BC but the idea received no real support until the sixteenth century when Nicolaus Copernicus suggested the notion of a Sun-centred system.
The invention of the telescope in 1608 by the Dutch spectacle maker Hans Lippershey was the real turning point in our ability to study objects in the Solar System, and therefore understand their origin. With this wonderful new invention and its slightly modified successors, astronomers uncovered some of the great mysteries of our planetary cousins, but the discoveries were always limited. The attempt to see any fine detail was restricted by the conditions in our own atmosphere through which the incoming light had to pass. Not only was cloud a problem but the amount of dust and pollution in the atmosphere grew as industry slowly developed. All this as well as a very unstable atmosphere often made the image jump around, as though being viewed through a pan of boiling water. The only solution was to get up close, and to do that required getting telescopes, and indeed people, above the Earth’s atmosphere.
The technology needed to travel into space started to emerge long before any thoughts of actually doing so. Many people will be familiar with the experimentation of the Chinese with gunpowder, but the first signs of rocket propulsion appeared around 400 BC when a Greek by the name of Archytas suspended a water-filled wooden bird on a string above a fire, the escaping steam providing the propulsion. In its simplest form, this is the first documented appearance of Newton’s law of motion, which dictates that every action has an equal and opposite reaction. A few hundred years later, another Greek known as Hero who lived in Alexandria produced what could be considered a precursor to a motor, based on the concept of action and reaction. A fire was lit under a bowl of water which had two vertical tubes above it. The tubes collected and channelled the steam into a sphere which had two L-shaped tubes on opposite sides, allowing the steam to escape and causing the sphere to rotate.
It is difficult to pin down the original appearance of a chemical rocket but the Chinese were certainly among the earliest to experiment. It is thought that they may have realized the potential of such rockets during religious festivals when throwing bamboo sticks filled with a gunpowder-like substance on to fires to create explosions. There is a good chance that rather than explode, some of them will have shot off out of the fire, giving those who watched the idea of using chemicals to propel objects. They started experimenting with arrows attached to bamboo shoots filled with gunpowder in order to propel the arrows further when fired from a bow. It is believed that they then realized they could dispense with the bow and just fire the arrows using rocket power alone.
The first use of what might be considered the precursor to the modern rocket was during the battle of Kai-Keng in 1232, when the Mongols were at war with the Chinese. The Mongol army was held back by the Chinese who used what was later recorded in history books as ‘arrows of flying fire’. What seemed frightening to the Mongols was a simple form of rocket – a tube blocked off at one end and filled with gunpowder. Once the gunpowder was ignited, the ‘flames’ escaped out of the open back producing thrust which propelled the rocket forward. Directional control was maintained by a long stick that protruded out of the back of the rocket to keep it going forward.
There were many subsequent developments and enhancements of these primitive rockets but perhaps the most relevant for space exploration was made by the German firework manufacturer Johann Schmidlap some time in the 1500s. He invented what became known as the ‘step rocket’, which was the forerunner of rockets like Saturn V, which launched Armstrong, Aldrin and Collins to the Moon in Apollo II in 1969. Schmidlap’s invention was a multi-staged firework which used a large rocket to carry a second smaller rocket higher in the sky so that when the first rocket engine came to the end of its burn, it ignited the second rocket. Of course at the time this was used only for firework displays but the concept was later used, and still is today, for launch vehicles.
A wonderful sixteenth-century Chinese legend suggests that the first human to attempt transportation by rocket was one Wan Hu. He was said to have constructed a rocket-powered chair that was suspended under a kite that had around fifty Chinese ‘fire rockets’ built on to it. At his command, Wan Hu’s assistants lit the rockets and, so the legend goes, there was a tremendous roar and clouds of smoke, but by the time the smoke cleared, Wan Hu had vanished. His body was never found and no one really knows what happened to him, although it is likely that instead of racing off into the heavens on his rocket-powered chair, the contraption exploded, blowing Wan Hu to pieces. Thankfully modern rocket flight is a little safer than that, although there have of course been tragedies. In the first fifty years of space flight eighteen astronauts have died in four separate accidents: in 1967, a parachute failed to open on Soyuz 1 after it re-entered the Earth’s atmosphere; Soyuz 11 decompressed in 1971 just after undocking from the space station; in 1986 the Challenger space shuttle disintegrated after launch; and in 2003 the Columbia shuttle disintegrated on re-entry.
Space exploration has come on in leaps and bounds since the rocket was first invented. In 1961 cosmonaut Yuri Gagarin became the first person to complete an orbit of Earth, and just eight years later the historic Moon landing occurred. Then focus turned to the development of some kind of habitable space station, which differs from a spacecraft in having no form of major propulsion or landing system. The first space station was Salyut-1, which was launched in 1971 and, like its early successors, was designed to be sent up in one piece. Things changed in 1986 with the launch of Mir and then the International Space Station (ISS), both of which were modular systems, designed to be launched in stages and built in space. At the turn of the twenty-first century the ISS was the only operable space station in orbit, which has now been permanently manned for over fourteen years.
Those individuals who have travelled into space have by and large been highly trained and carefully selected. But that doesn’t stop the rest of us from dreaming. From Buzz Aldrin to Buzz Lightyear we venerate astronauts as heroes, as people we respect and often try to imitate. So how exactly can the rest of us follow in their footsteps? Clearly, before space travel can become routine things need to change: it needs to become easier and safer and it also needs to become cheaper. But we are well on the way. With the recent birth of space tourism a seat on a sub-orbital space flight costs in the region of £150,000. The chance to go into space properly – and by properly I mean experience orbits of Earth and hours if not days of weightlessness rather than just take a trip up and straight back down again – costs in the region of £20 million. That’s a lot of pocket money. Both of these may be unobtainable for the average person in the street, but these commercial space programmes none the less mark the first time untrained members of the public can buy their way into space. It is a giant leap in a very interesting direction, and who knows where it will take us in years to come.
For now, though, most of us will have to seek solace in the power of the imagination. I still think back to my childhood and my fantasy of becoming a ‘spaceman’, coloured as that vision now is by real-life missions, reports and discoveries. Even with all the things I have now learned about space and the Universe, my mind still wanders as I picture myself flying around the Solar System, visiting each of the planets in turn. So what would such a journey be like? What would one see and feel and experience? This book is about that journey.
We’ll start by looking briefly at the mechanics of the Solar System and our knowledge of planetary movement, which will allow us to plan a route and prepare for the journey to come. Leaving the Earth and Moon behind, your voyage will first take you to the inner Solar System to visit the Sun, then Mercury and Venus, before swinging past the Earth again on your way out of the inner Solar System. After passing the red planet Mars you’ll head through the asteroid belt and beyond. The first gas giant planet you’ll encounter is the largest in the Solar System, Jupiter. Saturn, Uranus and Neptune are next on the itinerary before you immerse yourselves in the mysterious objects that live in the depths of interplanetary space.
This book is an extension of my dream, and the dreams of many others, to see if at least in theory it is possible to fly around the Solar System and visit alien worlds. Join me now and prepare to depart on your very own space mission.