‘The only true voyage of discovery, the only fountain of Eternal Youth, would be not to visit strange lands but to possess other eyes, to behold the universe through the eyes of another, of a hundred others, to behold the hundred universes that each of them beholds, that each of them is…’
Marcel Proust, À la recherche du temps perdu
While a human being has not yet ventured beyond the moon, legions of our robotic spacecraft have scouted ahead, extending our senses across the solar system. All the planets have now been visited, transforming our knowledge and overturning our expectations. Lately it is these envoys that have been grabbing all the headlines – Rosetta and its lander module Philae have explored a comet; the Cassini probe has revolutionized our understanding of Saturn, its rings and its moons, and ended its life crashing into the planet. The New Horizons’ spacecraft photographed Pluto in exquisite detail for the first time in 2015.
Such spacecraft have stretched our engineering capabilities to the limit. Building a vessel to travel even the relatively short distances to the nearest planets is hard. It was especially hard in 1964, when no one had built a successful interplanetary spacecraft.
In the first few years of the 1960s, the Soviets had already launched a number of robot emissaries to Mars. All of them had failed, but they hadn’t given up. America in the meantime was basking in the success of Mariner 2 (Mariner 1 was destroyed after a launch anomaly), the first spacecraft to ever reach another planet, which in 1962 successfully journeyed past Venus, sending back data about the planet, before being cut adrift, locked in an endless orbit around the sun. Mariner 2, like a licked finger held up to the solar wind, had given American scientists a flavour of what was possible. Mars was now in their sights. And the building of such a craft, a ship that could sail further than ever, lay with the shipbuilders of NASA’s Jet Propulsion Laboratory (JPL), nestled in the foothills outside Pasadena and led by William H. Pickering. But this project would require a complete redesign. Something more sturdy and watertight, for a journey significantly more treacherous and complex. And with a lot more at stake.
In 1964, our best images of Mars were still fuzzy blobs of light and dark. What was needed was a camera that could sail right up to Mars itself, take some snaps and report back. Film of course would be of no use here. The camera and the spacecraft were never coming back, and so what became the world’s first digital camera was conceived and built by a team at JPL, led by the esteemed Caltech physicist Robert Leighton. It would be a camera that could turn an image into digital data recorded on a magnetic tape, which could then be beamed back home. Twenty-two 200 by 200 pixel photographs would be taken of the planet’s surface during a single fly-by, to give us ten times better resolution than we could see from earth. A hundred metres of magnetic tape was used to capture the images, averaging around $3.8 million a picture. There would be no second chances. No forgetting to take the lens cap off.
Work was started on a pair of identical twins – Mariner 3 and 4. The core of these two spacecraft was an octagonal magnesium ‘bus’ frame which housed the electronics, and hydrazine course-correcting propulsion systems – this was the architecture that became the signature blueprint design of JPL’s spacecraft that were to follow. Four extra-large solar panels jutted out, giving it the appearance of a giant flying windmill.
As well as the space camera system, there was a host of other scientific equipment: a magnetometer, and cosmic ray, dust and radiation detectors, ready to test the waters and take the pulse of Mars. Perhaps the most important innovation was the navigation system. Like mariners here on earth, the Mariners would be guided by the stars. In this case, the bright star ‘Canopus’ would be the guiding light.
Launch of Mariner 3 on an Atlas rocket was on 5 November 1964 at Cape Kennedy, but the protective ‘shroud’ on top of the booster failed to jettison as it left the atmosphere, and it was lost for ever. The mission’s success was left to the twin Mariner 4. The shroud’s technical problems had to be solved in record time, in order to launch it during the short window of time available to make it to Mars before it sailed out of reach. Three weeks later, and with the Soviet Zond Mars probe scheduled for launch only days away, on 28 November Mariner 4 was off on its 228 day journey to Mars, with 325 million miles of deep space to navigate. It managed the journey with only one mid-course correction en route.
One of the main concerns was control of the digital tape recorder. It would sweep across the planet, snapping the series of images of about 1 per cent of the Martian surface. With its primitive computer, sending commands to the spacecraft was a perilous procedure. One major worry was that a command to stop the tape recorder from running (the ‘off button’) wouldn’t work, and that the images would be wiped over, or not leave enough room for all the pictures intended. Mariner 4 flew by Mars on 14 and 15 July within a range of between 9846 and 12,000 km, taking twenty-one (and a few lines of number twenty-two) pictures in a twenty-five minute session. After reappearing from behind the planet, it began the arduous task of sending back the data collected at 8 1/3 bits per second: it would take many hours for the first image to be downloaded and processed, and nearly three weeks to transmit all the data in duplicate. For the first time in human history our eyes had been on another planet, and the world was waiting impatiently for the results.
Expectation was high from the world’s media, anxious to see the first picture of Mars from space. But the stream of data that chugged back to JPL via Goldstone tracking antenna in the Mojave Desert as a series of ones and zeros would still have to be processed by computer to create the actual images. It would be days before all the images could be seen. Eager to see if the tape recorder had worked as planned, engineer Richard Grumm and John Casani, who had been working on the tape recorder, decided to jump the gun and get creative. Data from Mariner’s camera was being converted into printed numbers on paper and spat out by a machine. The paper for one image was cut into long strips and arranged vertically side by side on a large room dividing board – the team began to colour in the strips using pastel crayons hastily bought from a local art shop. It was the most expensive painting-by-numbers art project ever created.
As the engineers began hastily colouring away, the Martian landscape swam into view – at the bottom, the numbers that denoted the blackness of space gave way above to the red and brown and yellow hues of the planet’s limb (edge) and surface. The hand-shaded picture turned out to be remarkably accurate when compared with the actual photograph processed some time later.
For the engineers involved, this was a way of demonstrating the tape recorder had worked. But the significance of what was unfolding as the image took shape drew crowds of JPL workers to gather round and watch, while an armed guard prevented the eyes of the press seeing what was to become our first (beautifully false) colour view of another planet taken from space.
The picture is now framed outside what was the office of William H. Pickering, the founding father of JPL. Our first image of Mars from space was realized not by a machine, but by the flow of human hands. Its place in space history is clear. But it is also the most important piece of American modern landscape art ever created.
While our robotic spacecraft’s primary function is to explore on our behalf, it can also carry with it something of us. The Zond 2 Soviet mission to Mars supposedly carried a commemorative pennant destined for the Martian surface. Closer to home, the LAGEOS (Laser Geodynamics Satellite) ‘Space Geodesy’ was launched in 1976, a strange-looking disco-ball built at the Marshall Space Flight Center designed as a laser-ranging reflector in orbit, bouncing back laser beams to make very precise continental drift measurements on earth. It has a solid aluminium shell covered in reflectors and a heart made of a solid cylinder of brass. On board is a small plaque designed by Carl Sagan – a time capsule for the people of earth in the year 8 million, which was how long it was thought LAGEOS would remain in orbit. The plaque has a map of the movement of the continents over time and the numbers 1 to 10 in binary. The NASA press release ends with: ‘Whoever is inhabiting earth in that distant epoch may appreciate a little greeting card from the remote past.’
Pioneer 10 and 11, launched in 1972 and 1973, were our first interstellar messages in bottles – thrown out into the deep water, dispatched to photograph and explore Jupiter and the interstellar medium, and now lost for ever. On board both spacecraft was the famous gold-plated plaque designed once again by Sagan and astronomer and SETI (Search for Extraterrestrial Intelligence) founder Frank Drake, which among other references to our planet had a line drawing of a naked man (waving) and woman drawn by Carl Sagan’s then wife Linda Salzman. What was deemed suitable for any alien civilization was considered too risqué for some of the inhabitants of planet earth, and genitalia were swiftly airbrushed out in the American press; there was also criticism by those who saw the image as portraying the woman to be subservient to the man.
THE FURTHEST WE’VE EVER SAILED
‘I must go down to the seas again, to the lonely sea and the sky,
And all I ask is a tall ship and a star to steer her by,
And the wheel’s kick and the wind’s song and the white sail’s shaking,
And a grey mist on the sea’s face, and a grey dawn breaking.’
John Masefield, Sea Fever
The two Mariner-class spacecraft named Voyager 1 and 2, launched in 1977, have set the benchmark for deep-space exploration. What was originally intended as a grand tour of the outer planets of Jupiter, Saturn, Uranus and Neptune has became a symbolic extension of our most profound quest to explore. It’s a quest that is still going forty years later. If you go into the Theodore von Kármán lecture theatre at JPL in Pasadena, on the left-hand side wall you can see an insect-like Voyager spacecraft up close. It’s built from flight spares, so who knows, maybe if you asked really nicely you could get them to fire it up for you. It’s dominated by the huge white high-gain antenna dish sitting on a decahedral bus similar to the Mariner, which contains the brains of the spacecraft. Jutting out of this body like spindly limbs are the 13-metre magnetometer boom, the plutonium-powered RTG (radioisotope thermoelectric generator) battery kept well away from the main body of the craft and, on another boom, the various scientific instruments including the scan platform with Voyager’s eyes and ears. It’s a remarkable piece of engineering, designed to function unsupported in the most hostile environment of deep space.
But how can you travel such vast distances using only rocket propulsion? How could you carry enough fuel and escape the gravitational pull not just of the earth but of the sun? At the time, getting beyond Mars and Venus seemed impossible. The solution was ‘gravity assist’, which changed the way we think about travelling long distances and is important to know about if you want to travel to the outer solar system and beyond.
Let’s assume you’re in your spacecraft. As you approach a planet (which itself is in motion, orbiting the sun at tens of thousands of kilometres per hour), as long as you’re careful not to crash into it, you can use its gravitational pull, capturing some of that energy to ‘sling-shot’ you further and faster into space – perhaps towards another planet, which in turn can bounce you out even further. It’s a useful trick that every space explorer should know and one that requires no fuel. In 1961 a young maths PhD student called Michael Minovitch who was studying at UCLA figured out the fiendishly difficult ‘three body problem’ in mathematics: in our case, how something small like a spacecraft is affected by the gravity of two more massive objects such as the sun and a planet. Minovitch calculated hundreds of different pathways to the planets, theoretically bouncing limitlessly from one to the other. In 1965 Gary Flandro, another young student, spotted one very special planetary alignment of Jupiter, Saturn, Uranus and Neptune, all of which were nicely lined up in a specific time period between 1975 and 1978. With the maths in place and the planets lining up in a window of opportunity that wouldn’t open again for another 175 years, the engineers at JPL would only have one chance. A golden opportunity to sail further than we’d ever been before. The engineering challenges of such an ambitious mission were daunting and were overseen by project manager and engineer John Casani who had worked on the Mariner programme.
HELLO FROM THE CHILDREN OF PLANET EARTH
‘I get a gasp of surprise at two numbers that I give out when I describe the project. The first is: I worked on something that’s going to last for a thousand million years… But we had to do it in six weeks – and that’s when the real gasp comes.’
Artist Jon Lomberg, one of the instigators of the Voyager spacecraft’s Golden Records
Here was a chance that two man-made objects would be ejected from our solar system and essentially last for ever, orbiting the centre of our Milky Way galaxy with the tantalizing prospect of one day being intercepted by another space-faring civilization. John Casani approached Carl Sagan to provide something like the Pioneer plaque that could be carried on the Voyagers – Carl worked with a select group of scientists, academics and thinkers to come up with an idea for something. In January 1977, the astronomer Frank Drake had the idea of creating a phonograph record, which coincidentally was celebrating its one hundredth anniversary since its invention by Thomas Edison in 1877. The physical groove of a record is the perfect medium to store information indefinitely, something that can’t deteriorate or be wiped over like a magnetic tape. It would be made from copper and gold-plated. You might raise an eyebrow at the 1970s technology, but as we all know vinyl never goes out of fashion.
But what to put on the ultimate mix tape? One hundred and twenty-two images reflecting the diversity of life on earth were encoded in the audio spectrum – a breastfeeding mother; an eagle in flight; the diverse landscapes on earth – as well as greetings in fifty-five languages, including: ‘Paz e felicidade a todos’ spoken by a young Janet Sternberg. On the cover would be coded clues to the origins of this unusual spacecraft. And music. Music seemed like the perfect universal language, common to all civilizations here on earth, but with limited space and only six weeks to do it, how do you choose the music that best represents all cultures? Consulting various experts from around the world, music was chosen to reflect every continent and every epoch, everything from Beethoven, to Bach, to Chuck Berry, to Azerbaijani bagpipe music, a process which became a frantic exercise in ethnomusicology, speed and politics. The Beatles, for example, couldn’t be used because the request for ‘Here Comes the Sun’ was turned down by the band’s record company – presumably they couldn’t get past the legal ramifications of ‘in perpetuity, across the known Universe’. Ann Druyan, the creative force behind the project, who would later marry Carl Sagan, reflected on the final piece – the Cavatina movement from Beethoven’s String Quartet No.13 – in a BBC radio interview. She had been looking through excerpts from Beethoven’s diary: ‘ “Will they like my music on Venus? What will they think of it on Uranus?” At last, a way to respond to that impulse. To that question that Beethoven felt so very long ago.’
For the first time, these two spacecraft were to reveal the realities of the distant outer planets. The swirling atmosphere and famous red spot on Jupiter – a raging storm – were seen in sharp clarity. Jupiter’s moons, first seen as dots by Galileo Galilei centuries before, were now visible up close, with Io’s huge volcanic plume, 270 km high, seen for the first time. Saturn’s rings could be seen for what they were – as multiple rings within rings, with tiny ‘shepherd’ moons embedded within them.
Here, the two Voyagers parted company. Voyager 1 diverted to investigate Saturn’s moon Titan, heading up out of the plane of the solar system, its last official planetary encounter, while Voyager 2 carried on to explore Uranus, and then Neptune – the giant blue planet guarding the edge of the solar system like a sentinel, with its moon Triton with frozen nitrogen ice caps and nitrogen geysers. The Voyagers completely rewrote how we saw the outer solar system. Not just as distant static objects but as destinations. The solar system was alive.
Some twelve years after this epic journey started, the final picture from both spacecraft was taken by Voyager 1 on Valentine’s Day 1990. In its elevated position, its cameras were turned around and a group family portrait was taken of all the planets together, a mosaic, all except Mars and Mercury, which were obscured by the brightness of the sun. It was the picture of earth that grabbed the world’s attention. A tiny blue dot suspended in a beam of scattered light, the earth as a mere pixel seen from over 4 billion miles away. It is one of the most important photographs ever taken. The ultimate exercise in perspective. An image that shows the stark reality of our place in the cosmos, set free from our ‘imagined self-importance’.
Forty years on, the two Voyager spacecraft are still going. Their instruments are gradually shutting down. The engineers who built and cared for them can mark the milestones in their lives against the Voyagers like a yardstick – children born, falling in love, marriages ended, friends and relatives passing away. Right now the Voyagers have passed the ‘heliopause’ – that demarcation line like a lapping shore, where the solar winds can no longer be felt. They have crossed a point that marks the shallow waters of our solar system into the deep waters of the interstellar medium – the space between the stars. Voyager 1 is now 12.9 billion miles away and Voyager 2 is 10.6 billion miles.
Out in the benign depths of the Milky Way, they will not rust or decay. These two spacecraft with their ‘murmurs of earth’ will outlive everything we know. Our most distant emissaries travelling for ever through an ocean of space and time, a snapshot of our moment in the sun. The Voyagers weren’t just built to last – unlike us, they were built to last for ever.
‘I can sense stars, and their whispers amid the roaring of our own Sun.’
Voyager 2, via Dr Paul Filmer
TRAVEL GUIDE: HEAD OF SPACE AGENCY
Name:
Professor Johann-Dietrich ‘Jan’ Woerner
Profession:
Civil Engineer
Claim to fame:
Director General of the European Space Agency
What can I do for you?
There are few better people for some final thoughts on leaving the planet than the Director General of the European Space Agency. I read somewhere that you used to build rockets as a kid?
Yes. A lot. Different types with different propellants – I tried the liquid propellant, I did not succeed, but a lot of different solid propellants.
Were you aware of the history of spaceflight? Particularly early German rocketry?
Of course. Whether Germans or non-Germans, this was all close to my heart since the early 1960s. Space for me started in 1957. I was three years old and my father took me on his arm and said ‘Okay, look, up there…There’s Sputnik!’ and he said it so strongly I really believed I could see it. So that was the beginning. And afterwards I was really thrilled by space, so I built rockets and all of this stuff.
Those early rocket pioneers were inspired particularly by the science fiction of the day.
Jules Verne’s Journey to the Moon was also one. And interesting enough, the launch site was in Florida! All of these different visionaries inspired me.
As a kid it seems you were already in space.
Yes. We are all in space. We are astronauts on the spaceship Earth.
I think people wanting to leave the planet forget they’re already in space.
Exactly.
What is it for you that makes a good astronaut? There is a common thread, a confidence and good humour running through the handful of astronauts I’ve met.
It’s a balance between self-confidence and team ability. So he or she must be self-confident and strong enough to take responsibilities, but able to work together with others. And this balance, I think this is something that makes a good astronaut, because we need people who can make decisions while they’re on a trip and at the same time they should be able also to follow others and this is a challenge for people. The other things you can learn how to deal with, scientific things, but to have a balance between these two behaviours, this is something I think you cannot learn. Either you have it or you don’t.
We’ve got the ISS now until hopefully 2028. We hear a lot from NASA, Elon Musk and others about going to Mars. I wondered if you could give us your thoughts on where we’re heading for. ‘Space 4.0’ – the next chapter.
It is very clear to me that you must learn to travel through space. We’ll travel beyond the moon. We’ll travel even beyond Mars. It’s only a question of timing. I’m quite sure that humans will do that. If we survive. Stephen Hawking said it was the other way round, ‘In order for us to survive, we have to leave’. I say, in order to leave the earth, we first have to survive.
Right now, I think going to Mars is very difficult. It’s much more difficult than to go to the moon. You can say, okay, it was difficult to go to moon some fifty years ago, but the difference is that we know the dangers of going to Mars from a health point of view. Also, if you go to the surface of Mars you need a rocket to come back. I cannot imagine that the journey will be possible with humans in the next ten to fifteen years. The Americans now have changed their wording, they are not talking about a ‘Journey to Mars’, they now say ‘Deep Space Gateway’. I think one can be a visionary, but this is really outside of any vision.
Therefore, I think it makes sense to go to the moon. In any case we have to develop technologies and the moon is a perfect stepping stone. It’s also interesting from a science point of view, developing technology and for space tourism maybe. So I think this is vision enough: let’s go to the moon in the next ten to fifteen years, and then we can also have dreams about going further into the universe, but for that we need totally different technology and this is not on the table.
Humans will go. For sure. They will go to an asteroid, they will go to Mars, they will go to other places in the universe. I don’t think that Mars is the ultimate goal – humans will go further.
And do the Americans agree? How closely do you work with NASA?
Very closely. They are also saying to go to Mars is a very long journey. They are talking now about the middle of the 2030s. I think this is the minimum time we need. We’ll see what Elon Musk is doing, but all the spacecraft we have so far are not really a solution to go to Mars. We know that the Apollo astronauts were very lucky. If you go with an Apollo spacecraft to the moon and you get hit by a solar flare, then you are really burnt. So they were very lucky that they returned safely. But we should not take such a risk when we go for two years on a trip to Mars and back.
Is our greatest challenge in getting to Mars an engineering challenge? Or is it biological?
I think both. But I think the engineering we can solve by funding. If we do not have a totally different propulsion system, and are dealing with today’s technology, then we still have the two-year timeframe. So I think the engineering and medical aspects are linked strongly with each other. If we can make the trip to Mars in a much shorter time, then of course the medical issue is reduced. But as long as we do not have that, then the medical issue is a very big one.
Presumably it comes down to politics as well. Who knows what the world is going to look like in twenty years’ time? How frustrated are you by the short-sighted political cycles you have to navigate?
Well, political cycles and space do not fit very well together. But look at me, I am elected for four years, and if I say ‘I’m only interested in things which can be done either in my first or second term,’ then it would be ridiculous. So we need people who are thinking to prepare for the future in the long term.
There is a common yearning among space pioneers throughout history, and I think even yourself, who see human spaceflight as our destiny. Would you agree that dream is still alive?
I think it’s still alive, I really believe it’s still there. We have these enthusiasts, we have people with visionary ideas, we have people thinking far, far beyond their own possibilities time-wise and commitments-wise, and we need those people as dreamers from the future.
I wanted to give you the last word in the book. For those people who want to leave the planet, what advice would you give them?
Dream. And do it.
