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OU Lecture 2007: Fifty Years In Space: Listen to/download the lecture

Updated Tuesday, 26th June 2007

The Open University's 2007 Annual Lecture by John Zarnecki reviews some nail-biting moments from the first 50 years of mankind's journey into space

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John Zarnecki

Can you believe that we have been in Space for fifty years? It's incredible. I find it hard to believe. Fifty years! But half a century ago a lot of people doubted that it could actually happen. In 1956, Sir Richard van der Riet Woolley was Astronomer Royal and Advisor to the government on Space. Everybody was listening very carefully to what he had to say on the subject.

"Space travel is utter bilge."

Which just goes to show – never believe the experts. The following year he might have thought very differently because on October 4th, 1957, the Soviet Union launches Sputnik 1.

(space sound effects)

It had four aerials transmitting this characteristic sound and it orbited the Earth once every ninety-six minutes. A month later the Soviets are at it again when Sputnik 2 is launched. It's bigger. It carries more instruments and this time there is a dog on board – Laika. Although there is enough food and water on board for ten days we believe that Laika actually died within a few hours in Space when the insulation in the cabin failed. But Laika was a national heroine and the Soviets had put a living creature into orbit.

(space sound effects)

The first US programme, the Vanguard Project, had its teething problems but in January, 1958, the Americans successfully launched Explorer 1 which goes into orbit and it discovers the radiation belts around the Earth, the Van Allen Belt – a very important discovery, the first of many, many scientific discoveries made from Space.

So the US is in the Space race and it's rocket launch after rocket launch. Sometimes it seemed almost every week. The Soviets put a man into orbit.

(space sound effects)

The US responds. The Soviets space walk. The US take a stroll out there as well. I can't convey to you the excitement that this generated for me, a young lad growing up in the Sixties at the same time that Space exploration was well and truly beginning. I can't imagine how you couldn’t get caught up in the excitement of this time.

(space sound effects)

The triumphs, the disasters, the impossible achieved. It was a truly incredible time when one event could pull together entire nations in a breath-holding moment. I have to confess that for me it was the drama of the whole thing that grabbed me as much as the science and the technology of it.

Now I’ve called this lecture Fingers Crossed – Fifty Years of Space Exploration because, when I step back and think about it, despite all the fabulous technology, all of the testing that we do to make sure that things go right, sending missions across the Solar System is an incredibly risky business because we don't always know what the conditions are going to be like at our targets until we actually get there. That was certainly true in those early days and it’s still sometimes true today. Over the years as a space scientist, I have had my share of good fortune and bad fortune, with some great successes but equally the occasional problem along the way. And I would like to share some of those moments with you tonight.

Now, my first slice of good luck, I think, happened just to be growing up in the 1960s. It wasn't just the Beatles, the Rolling Stones, Pink Floyd, England winning the World Cup – I saw all of those live. But I really became hooked on Space exploration in 1961 and a chance encounter with this man – Yuri Gagarin – the first man in Space and overnight the most famous man on Earth. In the Summer of ’61 he embarked on a world tour. The UK was his first port of call. He met the Queen; he met the Prime Minister and then me. Well nearly. I was at school in Highgate in North London and Highgate’s most famous resident is here on your right. Karl Marx – Karl Marx’s grave in HighgateCemetery.

So every Russian dignitary had to come and pay their respects. We were given the afternoon off school. Now most of my friends went off to play cricket or football, play with their Game Boys or whatever it was you did in 1961. But for some reason I decided to go to HighgateCemetery to see what was going on. Here is Yuri Gagarin saluting Karl Marx. You can see this policeman here – I was standing just behind him. Just a few feet from Gagarin and to my surprise I was bowled over by the experience. This man – he was very small, much smaller than I expected. He seemed to be dwarfed by this big army hat that he was wearing and he had been in Space for ninety-three minutes. I couldn’t believe it. And that was the moment for me. I wanted to do something in Space. I didn’t know what but I wanted to have a part of it. So my mind was made up. I actually started to concentrate on my studies – well at least for most of the time – and I went to university and I got a degree in Physics.

But let’s just digress for a minute and ask ourselves, as astronomers, as planetary scientists, why is it we want to go up there? If we take a look at the sky – this is a picture taken by my colleague Phil Rosenberg from his back garden in Wolverton here in Milton Keynes – you can see the stars. There’s the Plough, the famous shape there. If you go somewhere a bit darker – up in the Lake District for example – and look at the same bit of the sky you get a slightly different view. You can see the Plough there but hundreds of stars now in the background. But they are twinkling. They are distorted by the atmosphere. For an astronomer it's like looking through a dirty window. Now this is another picture; this is the Sombrero Galaxy. This is taken by Steve Otter and Ollie Butters, two of our PhD students. They were working on the Open University course, "Observing the Universe" in the observatory in Majorca – a better view there – very good observing conditions. And you are beginning to see some structure in the Galaxy.

But if, instead of going a few hundred miles south to a nice site, you actually go a few hundred miles up above the atmosphere, this is what happens. This is the same object taken from a telescope on a satellite. You are seeing much more detail there. You are beginning to see the structure in the Galaxy and that lane of dust in the plane of the Galaxy. Now, I have been saying “see the Galaxy” but when we say “see” we don’t always mean “see” – as we do with the eye – in visible light, because visible light is only a tiny part of the entire gamut of radiation that exists. There is radio, radiation, X-rays, infra red, ultra violet – many, many types of radiation – and these are conveying lots of information about objects in our Universe.

Now most of this radiation is absorbed by our atmosphere, which is great for us as human beings because a lot of this radiation of course is very harmful. But it's not so great if you are an astronomer. You want to see this radiation because it's telling you so much. So lets have a look at this Sombrero Galaxy in other radiation, in other light. This is an image in infra-red light, taken again from above the atmosphere. It's beginning to look a little bit different and that dust lane as we call it around the Galaxy is now glowing rather brightly. That’s the region in red because dust emits lots of infra-red radiation. Now here it is again, seen in X-rays. And now it's looking very, very different. That’s because normal stars and dust – they just don’t emit in X-rays. We are now seeing completely different objects and processes – in fact some of the most exotic and violent events in the Universe. We are seeing massive stars and we are seeing material being sucked into black holes, being heated to incredible temperatures. So by being able to see different radiation we see a whole range of different processes and different types of objects. Now remember, these images, these last few images, would be inaccessible from the Earth. So we need to go above the atmosphere. How? Well, we put our telescopes on orbiting satellites and get rid of the effect of the atmosphere.

Now, back in the seventies it wasn’t so easy I was a student then. There I was. Trying to look like John Lennon, I think. And there weren’t too many opportunities to launch satellites just for astronomy. So we did the next best thing, we used something called a sounding rocket. It's really a glorified Guy Fawkes rocket. You light the blue touch paper; the motor fires for about forty seconds and, if you are lucky, you go two or even three hundred miles above the Earth, above the atmosphere. And if you put your telescope on that and point it and do everything right you can do your astronomy in just a couple of minutes. Back in the early 1970s, after I got my degree, I found out that, if I went to LondonUniversity, I could actually design and build telescopes to go on the sounding rockets. I could go to Australia, to Woomera, to the rocket range there. I could launch them and I could get a grant to do all of this. I mean, how lucky was I? The subject was X-Ray Astronomy. It was a new subject; the first x-ray source had only been detected about nine years before. The person who did it subsequently won the Nobel Prize for it. If only I had been a few years older maybe it would have been me.

So I was riding the crest of that new wave of astronomy. So I signed up and I was given the task to build a particular x-ray telescope. This is what we built. This is called an x-ray spectrometer. What it was going to do was to take in x-ray radiation and to split it up into the different x-ray colours and analyse how many x-rays there were in each of those colours. We were going to point it at a particular object called a supernova remnant. This was a, had been a star. It had exploded cataclysmically, four thousand years before, and it threw out a vast cloud of material, which was still so hot that it was glowing – not in light – it was much too hot to emit light – it was emitting x-rays. And that was what we were trying to look at. So there we were at Woomera, a bunch of young scientists. Between us we had precisely zero years of Space experience. Luckily there were a couple of very experienced engineers on the project. I think they had been working for all of five years in space research. They were the veterans. Between us we got the instrument and the rocket to the launch pad. Now, in a minute I am going to play to you my recording of the last twenty-five seconds or so of the countdown. It's not a very good quality because this was an illicit recording. Woomera was a high security Ministry of Defence site so I had to smuggle the tape recorder in. Now, remember, this was my first ever launch. Let’s hear it. We were in a bunker about a hundred metres away, just under the ground,

(sound effects)

and at about minus fifteen seconds I had to make a decision as to whether we would launch or not. I’ve just said “Gas Okay, Jackie”. So that was the Okay. I was terrified. Everything crossed. That’s ten seconds to go, I think. Fingers crossed, toes crossed. Five … It was absolutely fabulous! I mean that sound, that blast wave went through your body. The rocket is already three miles up. It went up with enormous acceleration. It got above the atmosphere. The x-ray telescope pointed at the correct source on the sky to an accuracy of about a hundredth of a degree. It was a very, very challenging task and it pretty well worked. Well, up to a point.

I should say the data was sent by radio link back down to the ground, to the receiving station. And that was lucky because our luck ran out on the way down. The parachute should have opened so that our payload gently floated down. We could have used it again then on subsequent flights. Well, the parachute never opened. The payload hit the ground at about a hundred and twenty miles an hour. It was a mangled pile of metal. Still, I was able to get one small souvenir from that flight and I have got it here. I managed to smuggle it back under my jacket and I would like to show it to you.  (laughter)

This is the nose cone from the rocket. This is one of two nose cones that fitted over the top to give it an aerodynamic shape so that it could get up through the bulk of the atmosphere. It was got rid of at about forty seconds by explosive bolts and it sort of fluttered down and landed on the desert floor. And so I managed to get that back home. It looked rather good. It made a difference from all the Che Guevara posters on the wall that we usually had. (laughter)

So what happened? Four years of designing and building this and then analysing the data. What was the result? Well here it is. (laughter) You are speechless I know. (laughter) But to me this meant everything.

This is what we call a spectrum. To my colleagues not a high-resolution spectrum I admit. And the critical part, which I am sure you have noticed, is this bump. That was it. That was the detection of oxygen from this particular super nova remnant. It was glowing; the oxygen was glowing and giving out one particular x-ray colour. I was very, very proud of that. It was predicted but it had never been done before. An element had never been detected by x-rays from beyond the sun. And we did that. So this was published in a journal called The Monthly Notices of the Royal Astronomical Society, a very prestigious journal. And it is one of the papers that I still look back on with some pride. I can't say that about all the papers that I have written, I have to say. (laughter)


Now, every good lecture I feel, as we all know, has to have a picture of a kangaroo. And here is mine. (laughter) So why have I got a kangaroo? Well, rockets are actually quite dangerous objects. You know – lots of high explosive and there are all sorts of precautions that you have to take. And at Woomera they were very proud that in thirty years of operation they didn’t have a single fatality – well, at least a human fatality. There was one fatality and it was a kangaroo. Not this one. One of the payloads was found in the desert, was recovered,  it was another mangled heap of metal. And about thirty meters away was a kangaroo – dead – absolutely dead. Not a single mark on it. And the assumption was that it had been sitting there, minding its own business and this rocket had crashed down a few feet away from it and the poor thing had died of a heart attack. Poor old thing.


Okay. Well, hopefully, the Woomera experience gives you some idea of how I fit in to the fifty years of space exploration. I had my first five minutes in space.

Now let me move forward a few years, in fact to 1978. It was hard to get jobs in the late Seventies in the academic world so I moved to a company called British Aerospace in Bristol and they were working for the European Space Agency on a project called the Large Space Telescope. So I joined that project and I was responsible for overseeing the heart of a camera that was going to work at the focus of this telescope. Now you will know the telescope better as the Hubble Space Telescope, as it was later christened, and the camera was the Faint Object Camera. And unlike my Woomera experience, this was working mostly in the visible part of the spectrum and also the ultraviolet.

Now Hubble has been absolutely vital to astronomy because it has enabled us to see further and with greater clarity than ever before. At the time, the camera that we built was the most sensitive camera on Earth or in Space. And it turned out to be the longest-serving camera in orbit. It was only removed in 2002 after twelve years of operation. It is still a world record. It could measure, for example, the width of a human hair at a distance of one kilometre and it was so sensitive it could have detected a candle at half the distance to the moon.

(space rocket sound effects)

Now after a successful launch in 1990 – there it is going up on the Shuttle – Hubble was deployed from the cargo bay of the Shuttle. There it is with those enormous solar arrays to give it power. And we sat and we waited. Now I don’t have to tell you that Hubble had a few teething problems.


All right. Which bloody fool left the lens cap on!

Well, it wasn't quite like that. It was more a problem with the mirror, beautifully manufactured and figured – to the wrong shape. Nothing to do with me, Guv, honestly! My bit worked perfectly from the start.

So this is obviously an example of where our fingers weren't crossed tightly enough. Now by that time I had moved on to other projects but still I was desperately disappointed that it appeared to have failed. Well, as we know, eventually NASA launched a rescue mission three years later in 1993. They put on a correcting lens in front of the mirror and it worked fabulously. It was really worth the wait. Here, for example, is one of the early images from the Faint Object Camera that I worked on. This is Pluto and its satellite Charon, beautifully resolved as never before. And also, for the first time, we were able to see Pluto and to see some structure rather than just a blur of light. But of course Hubble is best known for some of the beautiful images that it produces, some of the visual images. Let’s have a look at a few of them. This is a spiral galaxy. You can see some of the stars and some of the beautiful structure there. A nebula with different colours representing different elements, different temperatures. The famous Orion Nebula. You can see Orion’s Belt and Sword with the naked eye. This is a region where stars are forming out of gas and dust before our very eyes. And one of the most breathtaking achievements of Hubble was something called the Ultra Deep Field. What Hubble astronomers did was to choose a tiny part of the sky – in fact it was the size of a pinhead held at arm's length – a perfectly anonymous piece of sky and we are homing in on it. And Hubble stared at it for one million seconds to build up an image.

And what did it find? Well, as it stared and built up the image it found that this apparently anonymous piece of sky actually was filled with thousands of galaxies. Each of these is a galaxy and each galaxy contains literally billions of stars. There are some people who believe now, I think with some confidence, that of these stars, maybe as many as ten per cent of them, also possess planetary systems. So I think you can see there the implication is pretty mind-boggling. And there is something else. You know that, when we look at the Sun, we are actually seeing the Sun as it was about eight minutes ago. That’s how long it takes light to reach us. If we look at some of the nearby stars they are light years away so we are seeing them as they were a few years ago. With some of these objects in the Hubble Ultra Deep Field, these are some as far as thirteen billion light years away. So we are seeing them as they were thirteen billion years ago. And, as I am sure as you all know the Universe is merely fourteen billion years old. So we are really looking back with Hubble, far, far back to close to the origin of our Universe. So Hubble really is the closest thing that we have to a time machine. It really does help us to look back in time.

Now my speciality for the last twenty years or so has actually been going to other planets and other objects in the solar system rather than merely, if I might say that, observing from orbit around the Earth. The first such object that I went to was Halley’s Comet – Halley, named after Sir Edmund Halley, the famous astronomer. And this was the destination for Europe’s kamikaze mission, the Giotto Project. It was called Giotto because the Italian artist Giotto di Bondone was the first one to give a realistic representation of a comet in his Adoration of the Magi. Now I had been working at British Aerospace, it was a wonderful experience but I actually missed the research environment in Academia. So I saw an opportunity to work on this project at the University of Kent as project manager for one of the ten scientific instruments on Giotto and I took that opportunity.

Now, what was Giotto going to do? Well, this is a typical image of a comet from the Earth. We see a head or a coma, as it's called – a bright condensation of light – and the characteristic feature of a comet, which is this tail which spreads thousands, tens of thousands, hundreds of thousands of kilometres across the sky. Gas and dust reflecting light. But what we didn’t know is what's at the heart of it all? What creates this? What causes this? What is at the centre of the cometary coma? We can't tell from the Earth, we are blinded by the light, the scattered light, and we just don't have the resolution, the ability, to peer in there. So the answer was to send a spacecraft to have a look. Now our instrument, the one that I was helping to design and build, was actually to look at the dust – the dust making up much of the structure. And we wanted to measure the size of the dust particles; its mass and also how it was distributed about the comet.

Now there was a problem. The closing speed, the relative speed between the spacecraft and the comet, was sixty-eight kilometres per second. That’s a hundred and fifty thousand miles an hour or from here to the centre of London in 1.2 seconds. I wonder how that would look on the speed cameras? Now, at that speed, a tiny particle, and I mean a thousandth of a gram, had the ability to destroy the spacecraft. There is so much energy at those incredible speeds. So that was why I called it a kamikaze mission. The likelihood was the spacecraft would be destroyed on its mission and it did also mean that all the data that we collected had to be transmitted back absolutely in real time. And we also had a dilemma. What to go for? What miss-distance to go for? I mean, should we go right for the centre, give us the chance to get the best quality data, but almost certainly destroy the spacecraft – or should we take the more conservative approach, maybe go for a miss-distance of several thousand kilometres? Presumably we wouldn’t get such good data but at least we would have a chance of surviving or at least getting closer. Well, I can tell you the answer. And the answer, ladies and gentlemen, is five hundred and ninety four – kilometres that is. That was the miss-distance that we chose by committee, three nights before the closest approach. We had all ten teams meeting. This was the last chance we had to make a fine correction to the trajectory of the spacecraft. Some of us, our team included, wanted to go absolutely for the centre. We wanted to go for broke. Others wanted to stand off a bit. I can't remember now why or how we came up with five hundred and ninety four but it was the compromise.

Anyway, how are we going to collect, with our instrument, our dust impact data? Well this is a cartoon of Giotto travelling through space. And you might be able to see that, at the front of the space craft, there is something called a bumper shield. Here we can see it in more detail. It had never been tried before in space. At the front there was a shield, quite thin, aluminium, a few millimetres thick, that would protect us against the very smallest particles. But the larger ones (large, remember, is thousandths or even less of a gram) would punch straight through and we then had a second shield here made of Kevlar, that’s the material that you make bullet-proof vests out of. The act of going through the front shield would spread the particles out and they’d impact over a wider area and that, we thought, would give us a chance to protect ourselves against all but the worst particles. Here we can see the team working on a flight spare of the front shield and what we did was to put our sensors on the rear side of that front shield. Here you can see some of them. And what these are essentially is very sensitive microphones. Every time a dust particle hit the shield it essentially set up an acoustic wave, a sound – it created a sound and our very sensitive detectors would pick up that sound. We also put some sensors on the rear shield to pick up those ones that punched through the front and got through the rear shield.

(launch sound effects)

Well, the launch was in 1985, summer 1985. Nine month journey to get to Halley's Comet. So I would like you to imagine the scene. We are now March 1986. We are in Mission Control, Europe’s version of Houston. It's in Darmstadt in Germany. It seemed that half of the world’s press is there. Science Ministers from all over Europe. Anybody who is anybody in the Space business was there. Frankly it was a bit of a circus. Two hours from closest approach, we are closing in. All ten instruments are on. The camera picks up in the distance a fuzzy blur. In fact we are just beginning to see a solid object at the centre of the comet, the first time that this had ever been seen – a cometary nucleus. The magnetometer is picking up magnetic anomalies. The plasma instruments are detecting gas flowing out of the comet. One by one the instruments are detecting data. We are on a corridor, ten different rooms with each instrument team. We hear the cheers, the shouts, as the instruments start to detect their data. All of the instruments are working – except for one. You can guess which one it was!

Our predictions had said that we would detect our first dust impact between minus ninety and minus eighty-five minutes. The clock kept on ticking. The minutes passed. Nothing. We were the only one not working. So there we are: the DIDSY team – we were the Dust Impact Detection System – sitting there at our monitors, very, very quiet. We were watching a row of zeros literally passing through our screen. Was DIDSY going to become DUDSY? Had our instrument packed up? Important scientific thoughts were going through my brain – such as, “Where could we hide?”  (laughter) “Who was responsible?” “Who could I blame” Then, thank the lucky stars, (ping) the sweetest “1” I had ever seen. It happened at minus seventy-two minutes. We had the first dust impact. It was wonderful. Fingers uncrossed, cheers went up. We were happy too. My goodness were we happy!

But we were still more than a hundred and fifty thousand kilometres away from the target but closing fast. We converted the data into a sound file so you could hear it as if you had been sitting on the front shield of the spacecraft. This is how it would have sounded when we were far out (sound effects) – just the occasional hit on the shield. We moved in. The hits started to build up. Twenty minutes to go and the spacecraft is beginning to take quite a battering. In fact, we now start to get the occasional impact on the rear shield, so bigger particles are beginning to bombard Giotto. Will the shields hold, Scotty? (laughter) We are now only minutes away from the closest approach. Whatever happens, it doesn't matter. It's a success. We have got lots of data. But how close could we get? Moments later and some of the data channels started to saturate, we are getting so many hits. We are within one minute from closest approach. And then – it happened. (silence) We lost everything. Screens go blank. We assumed a big particle – the spacecraft had been lost. But it had exceeded our wildest dreams. Cheers, hugs, the champagne started to flow. The end.

Well was it? No. We hadn’t finished the first glass of champagne before a voice piped up from the other side of the control room. We have still got some data. What’s going on? But there is something strange about it. It wasn't like before. (sound effects) It was coming through in bursts. We were getting a burst of data then a blank, then a burst of data again. What we think happened was that a particle had hit, probably on the very edge of the shield, and it had set the spacecraft nutating – or wobbling. Now the radio transmission back to the earth was in a narrow beam so, with the spacecraft wobbling, this meant that the beam was waving around. So it was literally going backwards and forwards across the Earth and we were just picking up bursts of data. But there was actually an on-board system to damp out the wobbling and, over the next twenty minutes the wobbling gradually died down. And so we had the situation about twenty minutes later that we were actually receding from Halley’s Comet still taking data, which we never imagined could happen. But actually, Giotto was not quite as before. The camera was blind. It wasn't sending any pictures. The temperatures were all over the place and actually fifty per cent of the instruments were dead. But DIDSY was alive, or at least ninety per cent of it was alive. Well, what do you do with a half-working comet-probe? Well, you send it to another comet of course.

But hang on. One small problem. We had virtually no fuel left. Well there is a way around that because in space there is something, we do have something, that is very close to a free lunch and it's called the gravity assist manoeuvre. If you send your spacecraft to fly past a planet or a large body, and if you get everything just right, the geometry,the speed and so on, you can actually use that planet to sling you off in another direction. You can change the course for free. And the clever people who were controlling the Giotto spacecraft realised that the orbit, it was actually an orbit that would bring it back to Earth, about four years later. So in 1990, Giotto flew over the rooftops. About a thousand kilometres. And it was shot off towards another comet – Grigg-Skjellerup – a comet that you will never have heard of – totally anonymous. But that is what we wanted. We wanted to compare it with Halley.

Well, what happened? We got there. At Halley we got about fifteen thousand impacts that we measured. At Grigg-Skjellerup we got three. A lot less active a comet and we were also travelling more slowly, relatively speaking, which meant that we had less sensitivity. Anyway, it was wonderful. We got more scientific papers. European taxpayers got wonderful value for money. (laughter) Giotto survived that too. We built it well. But what to do with it next? Well I actually formally suggested to ESA, because I worked out that we could actually crash it into the moon, not for a bit of fun – well it would have been fun to be honest – but I think we could have got some good science out of it. But that was a step too far for ESA. So it was sadly turned off. And where is it now? Well, it's trogging around the solar system, forgotten by almost everybody but certainly not forgotten by those who worked on it over twenty years ago. Actually I think this mission was very, very important for the European Space Programme. It really put Europe on the map in terms of the world exploration, space exploration scene. And from then on I think Europe and ESA was taken very seriously.

Well, what other instruments have been dear to my heart? Well, I would like to say something about my involvement in the Beagle 2 mission to Mars, led of course by my colleague Colin Pillinger from the OU. It's something that I am very proud of but, as you know, our fingers weren't crossed tightly enough on that occasion. Now of course Beagle got as far as being released from orbit around Mars. Everything was functioning well then. But we heard nothing more from it. We don't know what happened but surely some day we’ll find out.


Nevertheless my team built a meteorological station or a weather station to go on Beagle. That was our contribution to it. It was to measure temperature, pressure, wind speed – I don’t know if you can see at the top sticking up there – that’s the wind sensor. It would have measured wind speed and wind direction on Mars. We would have measured dust impact and we would also have measured for the first time the ultra violet radiation. And all of that for 160 grams. What was tremendous about Beagle was the way that everybody managed to miniaturise their instruments – most of them are shown there – to fit in a very tight space.

Now one of our main aims with the Met Station was to measure something called Dust Devils. These are mini tornadoes and you can see this in this wonderful clip. This is from the Mars Exploration Rovers, which are operating on Mars at the moment. You can see these things dancing across the Martian desert. Some of you might have seen them. They exist on Earth. But on Mars we think they might be very significant as they might help to trigger the global dust storms which sometimes completely envelope Mars. But that’s not the end of the story because the technology that we developed for that weather station on Beagle we have adapted, we have taken further and we are currently building to put on this probe, this Rover, this is ExoMars which is Europe’s next mission to Mars and we are working on that in the labs across the road right now, launch in 2013, fingers crossed. And the chemistry set which was on Beagle which was going to look for signs of life on Mars is now being developed also here in the labs for a completely different purpose – to test for tuberculosis in some of the poorest parts of the Earth. So you can see that Space is about more than producing non-stick frying pans.  Right, let me now go on to what is possibly my most favourite space instrument of them all, and it's this – or, at least, this is the first prototype that we made of it. This is the Huygens Penetrometer. And I will explain in a minute why I did that.


Now what is Huygens and what is Cassini? It was a joint mission of Europe and the US named after Cassini, who studied Saturn’s rings and Huygens who discovered Titan, Saturn’s largest moon, in the seventeenth century. This was a very ambitious mission. Two spacecraft to go to Saturn, to study Saturn itself, the rings and the many satellites of Saturn but in particular Titan. Titan is the only moon in the entire solar system with an atmosphere. It’s a very, very thick atmosphere and one that has some similarities to the primitive atmosphere that Earth had maybe four billion years ago. Now Titan was visited by Voyager 1 and Voyager 2 – two spacecraft which flew past in the early 1980s. And they produced about two thousand images, which in some senses were frankly quite disappointing. And this is probably the most exciting picture that they produced. They all showed this body completely shrouded in this orange photochemical smog or haze. Not a single gap in the haze to enable us to see to the surface.


Titan is a world of ice. It's not a rocky body like our own Earth. Nitrogen, like our own atmosphere, and methane. The surface was about minus one hundred and eighty degrees Centigrade, really, really cold. So with all of this information Titan clearly stood out as a target for special study, so that’s why the Huygens probe was chosen to eventually land on Titan.


Cassini-Huygens travelled for seven years to go to this place, to find out what was going on below the haze. That’s Huygens released on a collision course with Titan. It travelled for twenty-two days, slowed down by the very thick atmosphere, and then it deployed a series of parachutes to float down for two and a half hours through the atmosphere down to the surface. I was particularly interested in the surface. One of the things that Voyager had hinted at was that perhaps the surface was really rather exotic, partially covered by lakes or even seas of liquid methane. So my instrument, one of the six scientific instruments, was the Surface Science Package. We had nine sensors, some designed to work if we landed on a solid surface and some a liquid. And this one – the Penetrometer – this was the first prototype we made. It's three times the actual size. It was instrumented with a force transducer here, literally to measure the force of impact. And from a simple measurement like that we were hoping we would say something about the nature of the surface.


Here is a schematic. You can see Huygens under the parachute and here circled is the Penetrometer, sticking out through the front of the probe. Now the trouble is, of course, we didn’t know what we were going to hit. The camera might not have been working. We might have had no idea what it was we were landing on, not even whether it was liquid or solid. We might well have been destroyed on impact. There was no guarantee that the probe would survive so we had to send the data back instantaneously. Also, when we talk about impact data you have to remember that that impact would have lasted for less than a second. So we had to sample it very quickly and send it back straight away. In fact, think about it. We are talking about seven years of designing and building the instruments; seven years of travelling to Titan and then maybe less than a second of data. Now that’s not crazy – that really is bonkers!


Let me take you now to January 14th, 2005 – probably the most important day of my professional life. So this was the day that Huygens arrived at Titan. Remember, we had been working on this, or I had been working on it, for seventeen years, not a single piece of scientific output to show from it yet. So you can imagine it was just a little bit tense that day. There I was in the same European Mission Control Centre. The carpets had changed. The computers were a bit flashier but it was the same place that we had been before. We were waiting, waiting to see whether those seventeen years were wasted or not. I really don’t have the words to tell you how I felt – what the atmosphere was like. I won't even try. Then, 15.26 Central European Time – the screens filled with green figures. That told us that Huygens was transmitting from under its parachute, sending the data to Cassini and then back to the Earth. As before, cheers, hugs, screams, shouts. You know. You have heard it all before. The data was coming through.


Well what did we produce? This is what we produced – one floppy disk. This is the entire data take from my instrument – the Surface Science Package – the Penetrometer and eight other sensors. So there we were on the evening of January 14th with our figures. What did it all mean? We had foolishly promised that we would appear – all the science teams would appear – in front of the world’s press. We were going to tell them exactly what Titan was all about. So we had to come up with a story. Well, the data that we thought was the most reliable was actually the data from this instrument – the Penetrometer. There it is. What is it? A graph (we do like graphs, as you might have noticed) of force against depth as we push into the surface.


We were looking at this thinking what we were going to say to the Press. What had we done? What was Titan like? And somebody, we still argue about who it was, piped up from our team: We have landed on crème brûlée – look. We have hit something hard. There is a high force as if we have hit a crust. We have pushed through that crust and then there is something soft, thicker, beneath it. So half an hour later I and my colleagues faced the world’s Press. And what did I say?

So ähnlich wie crème brûlée according to the Berliner Zeitung. Similar to crème brûlée, I think it means. Well, maybe it was a quiet day for news but crème brûlée and Titan was picked up all over the world. There we are on the front page of the Independent. We even made the Sun. It was all over the place. But of course there were six instruments. Ours was just one of six. What did we learn from the other instruments? Well, there was a camera taking visible images. About a hundred pictures as we descended through the atmosphere. I am just going to show you one or two of them. The first image is from about a hundred and fifty kilometres, you can see the height there, showed absolutely nothing. We were peering into that cloud. All we are seeing is cloud. And many of the first images were like that. It wasn't until we got to about twenty-five kilometres above the surface where we started to get a glimpse of that surface. We weren't sure what it was but there was something there. A bit further down, fifteen kilometres or so, this is in fact a composite and we saw a remarkable sight. We were seeing what looked like river channels with tributaries feeding larger channels. And what was this? Was this a coastline? Were we in fact descending towards a sea or a lake of methane? The scale of this, by the way, is about five kilometres across. And then finally we landed and this is what we saw – an absolutely remarkable image. Looks like a desert but the camera at this point is very low down, just a few inches above the surface, so these pebbles, the largest one there is about six inches across. When I say pebbles, remember Titan is an icy world, so these are pebbles made of ice. So that’s the picture but what could we say about this scene? Well let’s take a look then again at our data. How do we interpret this? How would we relate this to the surface of Titan? Well, it's obvious isn't it? You go to B&Q in Bletchley and you buy some of this. (laughter) Now you probably think that this is material that you buy to make your garden look beautiful. But you are wrong. This is material which B&Q sells so that planetary scientists can make planetary surfaces. Either pebbles like these – these are sharp, angular pebbles. Maybe like the sort of material that you would get on a planetary surface if it was bombarded by meteorites and the surface was broken up. Or material like this. This is much smoother, much rounder pieces.


On Earth, of course, these are produced by the action of water flowing over rock, breaking, chipping off bits of rock and gradually smoothing them and rounding them off. Maybe the same thing is happening on Titan, not with water and rock but with liquid methane flowing down those channels that we see and taking off bits of ice and rounding and smoothing them off. So we ran lots of tests – literally hundreds of tests in the laboratory with material like this, lots of other materials to try to understand these graphs. Well, to cut a long story short, what we think has happened is that, despite what the picture shows you, we think that this little bit of trace here tells us that this whole surface is coated with a thin veneer of something soft. Maybe material, which has been raining down out of the atmosphere, sort of hydrocarbon coating on the surface. This peak here probably occurred when we hit one of these icy pebbles. We hit it, got a very high resistance, we pushed it aside and then we pushed down into this material between the pebbles, which is granular material but it's icy. So it's icy chips, probably of this sort of size and consistency. But what I can tell you for sure is that we didn’t land on crème brûlée! (laughter) What do we learn from all of this? Well one thing that I learnt is that pictures are great. They are wonderful. They tell you a lot. But go for the graphs as well. As scientists we love graphs and there is so much more information in them.
Now I would like to round off by talking just a little bit about disappointment and about science fiction. First of all I am going to tell you about my attempt to be an astronaut. It's going back to the 1970s. I was an avid
 Guardian reader then. Well, you wouldn’t expect anything else from an OU academic would you? And I found this advert. This was 1977 I think. An advert in the Guardian to be an astronaut. This was the search for Europe’s first astronaut to fly on the Space Shuttle and each member of European Space Agency made its own selection. So I applied. I got as far as the last thirty from the UK. It was beginning to get quite serious. We had very detailed medical and psychological testing. So I went through all of that. And then I got my “Dear John,” letter. Well “Dear Mr Zarnecki,” – I didn’t even have my PhD then. “I am sorry to say that your name is not one of those which has been put forward.” They told me it was my eyesight. I actually think that I failed the psychological tests.

Now I would like to turn to science fiction. I have talked a bit about going to a comet. We have flown past the comets. It's easy isn't it? We’ve done it. Let’s be a bit more ambitious. Think about going to a comet and landing on it and then, with the expertise that we have here at the Open University, we could build an instrument that could analyse the material in the comet. We know – we learnt from Giotto, for example – that a comet is actually eighty per cent water ice. Some people think that the water on Earth, most of our water, might have been delivered by impact from comets, early in Earth’s history. If we could go to a comet, look at the water and measure the sort of fingerprint of that water and then compare it with that same fingerprint here on Earth, we could decide whether that is indeed true. Did water come from comets? Also, some people say that the building blocks for life, the organic molecules, the triggers for life, might also have been delivered by comets. Again our instruments, built here, could look for those organics. Well, I can reveal to you that that is not science fiction. That is actually happening. This is a spacecraft called Rosetta and this is what it's going to look like – fingers crossed – on November 10th 2014. It was launched three years ago. It has already passed Mars. It's on its way to comet Churyumov-Gerasimenko – another comet you will not have heard of. (laughter) It has a lander, which will separate from the main craft. It will land on the comet’s surface. And the instrument built by colleagues at the Open University will make those measurements that I have described.

Now, talking of life, which I was, in the context of water and organic molecules, well these days when we talk about life in the solar system we think about some exotic places like Europa Enceladus, Titan and so on. But we always come back to Mars. Now we know with some certainty that Mars used to be very, very different. It was probably very wet. It had seas on it. Its atmosphere was thicker and it was almost certainly warmer. It was actually quite a nice place to be and it's quite likely that life could have got going on Mars. But things didn’t stay like that. Why?

Well, we know what Mars looks like today. It's like that. So Mars changed from its benign state into something like this. We would love to know why that happened. What triggered that change? Could it happen to us on Earth? But, more than that, supposing life did manage to get going – simple primitive life? We know that life is very smart; it's very tough. As the environment changed, might life have evolved? Might it, for example, have burrowed down below the surface to escape the dangerous radiation, which was no longer cut out by the atmosphere? Well, if that’s the case, could it still be there today or could there at least be the signs in fossil form? Well, what we would need to do is drill down below the surface to take a look. Perhaps something like this. That is ExoMars that I referred to earlier. So it is not science fiction. We are working on instruments to study the environment, the weather and especially the ultra violet radiation. It's never been measured. We know it's very, very severe but we don’t know how bad. Actually we predict that, to survive, for a human to survive exposed on the surface of Mars, you would need something like Factor 80,000 sun cream. (laughter)
So finally, really, to finish off – and this really is science fiction. I am just going to say a few words about my favourite place, which has to be Titan. We found with Huygens and with Cassini something about it. I have only told you a tiny bit. It's absolutely a fascinating place. Huygens sampled just a few hundred square kilometres of the surface with the pictures and so on. There is eighty million square kilometres of Titan. It's a wonderful place. So we want to go back but we want to go back with mobility. We want to study the whole surface. So what we need to do I think, is to go back with a balloon. We calculate that it would take something like two weeks to do an entire circuit of Titan being blown by the winds. We could do a few circuits, survey the whole surface, decide which were the most interesting bits and then go down to where the greatest interest is. Maybe scoop up, suck up some of the liquid; analyse it in the instruments on board here. And my dream is that some of those instruments will be built here at the Open University. Now it is science fiction today but I can pretty well guarantee that in maybe twenty years time this will not be science fiction. This will be happening in the second fifty years of space exploration.

So, Vice-Chancellor – if you would like to make an ageing space scientist very, very happy, ten million quid please and for that I will even put the OU logo on Titan for you! (laughter)

Fingers crossed. Thank you.





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