NARRATOR (SAMUEL WEST): Ten years ago, the Hubble Space Telescope was launched. And one of the greatest dramas in the history of space exploration began.

DR. CHARLES PELLERIN (NASA Director of Astrophysics, 1982-1992): The dream we all shared was that Hubble would be the greatest scientific instrument ever built and revolutionise how we think about our place in the Universe where we've been and where we are going.

DR. JOHN TRAUGER (NASA Jet Propulsion Laboratory): The cutting edge of astronomy's always been at just the edge of what you can see. What you can't quite see is still in the future. This was going to be the future.

DR. JEFF HESTER (Arizona State University): The real excitement came from the realisation that there would be things that would just surprise us, that showed us things about the Universe that we didn't even know beforehand we should be asking about.

NARRATOR: But a fateful turn of events was to lead to disaster. Unknown to anybody, one tiny flaw in its construction meant that the Hubble could not produce a sharp image. The grand goals of astronomy seemed out of reach. This is the story of how calamity turned to triumph and how the Hubble has since gone on to transform our view of the Universe. The Hubble telescope was designed to unlock the deepest secrets of space.

JEFF HESTER: What happens when stars are born?

CHARLES PELLERIN: What is the Universe made of?

DR. WENDY FREEDMAN (Carnegie Observatories): How big is the Universe, how old is the Universe?

DR. ED WEILER (Head of Space Science, NASA): How did it all begin, how did we get here?

NARRATOR: Hubble's greatest goal was to find the origins of the Universe. When and how did space and time begin?

WENDY FREEDMAN: It's basic human curiosity. We would like to know how the Universe originated, how did we get here, how did we eventually evolve to the point that galaxies formed and stars and planets and us? It's a central question.

NARRATOR: The birth of the Universe is one of the biggest mysteries in astronomy and it had perplexed the best scientific minds for centuries. Then in 1929 an astronomer called Edwin Hubble made a crucial discovery. He found that stars and galaxies are not in fixed positions in the sky. They are rushing away from us. The Universe is expanding. The implications for finding the age of the Universe were enormous.

WENDY FREEDMAN: If we know how fast it's expanding now then very much like in the case for a movie we can wind that backwards and we can see how long the Universe has been expanding at that rate, so it lets us get back at the issue of how old is the Universe and what were its origins, how did the Universe come to be.

NARRATOR: But there is one difficulty that faces all astronomers trying to answer these fundamental questions using telescopes on earth. They have to look through Earth's atmosphere, a turbulent layer of air hundreds of miles thick which blurs and distorts the light from stars and blocks some wavelengths of light completely.

JEFF HESTER: The Universe is not a place of only visible light. Stars that are much hotter than the Sun produce most of their light in, in far ultraviolet part of the spectrum. You just can't see from the ground. If you're trying to study newly forming stars that are buried down inside of clouds and gas and dust the only light that can escape from those clouds is infrared light. If you're going to see those objects you have to be able to see that infrared radiation, but again you just can't see it from the surface of the Earth.

NARRATOR: In the minds of a very few astronomers there was a solution, but one so ambitious that it seemed insane. Decades before space travel was possible, they dreamed of putting a telescope in orbit beyond Earth's atmosphere. It wasn't until the 1970s when space flight had become a reality, that NASA resolved to build a space telescope. They would name it Hubble. This was one of the most ambitious missions ever conceived. The Hubble would have to take pictures of the furthest reaches of space while orbiting at 17,000 miles an hour and transmit them back to Earth 400 miles below. Five new instruments had to be designed to survive the rigours of space, two cameras to image distant stars, two spectrographs to detect what stars are made of and a photometer to measure their brightness. The technical challenge was enormous.

JEFF HESTER: It was pushing the envelope in about as many ways as it could push the envelope. No one had ever made optics that were that exquisite, much less tried to make them work above the Earth's atmosphere.

DR. DUCCIO MACCHETTO (Space Telescope Science Institute): What we were trying to do is to build something that will measure the lights of objects that are maybe 10 or 15 billion light years away from us, they travel through most of the Universe, they get to us and they are extremely faint.

ED WEILER: That's not easy when you're flying in space 17,000 miles per hour. You've got a, you've got a 40ft long telescope that weighs 25,000lbs with large solar panels.

JOHN TRAUGER: And we can't touch it, we can't get out a screwdriver even, we can't change a thing. It has to be perfect, it has to run without any maintenance of any kind for years.

CHARLES PELLERIN: At some points we had, I'd estimate, 10,000 people working on this project building some component of it. As an system it's incredibly complex.

NARRATOR: The greatest challenge was to build the huge mirror at the centre of the Hubble. It was this mirror that was destined to cause the drama that would put the entire mission in jeopardy. The mirror's precise concave shape was designed to receive the light from stars and reflect it onto a secondary mirror that could be adjusted for focus. From there the light would reach the science instruments.

TERRY FACEY (Hubble Optical Physicist): The mission objectives of, of the Hubble Space Telescope were to, to observe objects 50 times fainter than we could do from the ground and with 10 times better resolution, so to meet those goals the mirror had to be at least 10 times better than, than any previous mirror. We were, in fact, going to strive for an almost perfect mirror, as close to perfection as we could possibly measure.

NARRATOR: NASA put the task of building the smoothest mirror in the world into the best possible hands: a company called Perkin-Elmer, who had made precision optics for spy satellites. In 1978 the company assembled a team of the best optical engineers in the world. Some would spend as long as five years designing and building the perfect mirror.

(ACTUALITY CHAT)

LOU MONTAGNINO: …what we do is we force them into, you know, we've got to see a model, we've got to see a model. He was drawing pictures faster…

MAN: …when they were trying to analyse what was going on the opticians were taking and moving the mirror 90 degrees and they're saying what the hell is going on?

(ACTUALITY CHAT)

NARRATOR: Bud Rigby was head of the team that polished the mirror. Lou Montagnino was in charge of testing.

BUD RIGBY: It was certainly a, a major milestone in astronomy. There was an awareness on the part of everybody as to the relative importance of it, yes.

LOU MONTAGNINO: I, yeah I think the, it was clear to all of us was a very, very significant job. We were pushing the state-of-the-art. Most people had no concept of how far that needed to be pushed.

NARRATOR: The mirror began as a huge chunk of glass that weighed nearly a tonne. First it was roughly ground into the right form. Then a specially designed computer-driven tool was used to polish the mirror to its precise concave shape, accurate to a millionth of an inch. Each polishing cycle could last as long as two days. Then the whole mirror had to be moved to a special vibration-proof chamber to test how its shape was progressing.

TERRY FACEY: And so the mirror would come into this room on its transporter. The transporter would elevate the mirror to the height of this platform and then the mirror will roll on, on its carriage on these rails into this vibration isolated platform and we begin the measurements sequence that tells us how well that polishing cycle, how, how well it did and so in the top of this chamber all the way 11 metres above the surface of the mirror is the main measurement instrumentation and the measurement instrumentation is what maps the surface of the mirror and tells us how successful was that last polishing cycle.

NARRATOR: High in the testing chamber was an instrument called a null corrector which sent calibrated beams of light from the mirror into a test instrument that checked its shape. So sensitive was the system that the slightest disturbance would make testing impossible.

BUD RIGBY: All the testing had to be done at night, right, and cars as far away as three or four miles on the highway would still produce enough vibration in the test chamber that they had to stop testing.

NARRATOR: After the tests showed the shape of the mirror, new polishing commands were programmed and the cycle began again. This part of the process alone took over a year.

BUD RIGBY: You lived on the clock that was established by the cycles on the mirror. We ran seven days a week, 24 hours a day. It was 16 months of devotion to the mirror.

LOU MONTAGNINO: It's, a typical day was 10-12 hours, OK, could run as high as 16 or more. It could, there were a few times that we could get out on a reasonable schedule but Bud and I had to be available at all times.

NARRATOR: Finally, some five years after its design began, the mirror looked perfect.

TERRY FACEY: The final polishing run was not known to be the final polishing run until after a measurement right here and, and so a night and several days elapsed while the data was, was analysed and then the metrologists declared the mirror finished. What jubilation. Finally we're there, finally this mirror is good enough to meet Hubble's performance specifications and we can declare it done.

ARCHIVE FILM NARRATOR: Perkin-Elmer is proud to have played a part in this remarkable technical achievement. Space Telescope will enable astronomers around the world to answer profound questions and formulate even more profound ones.

NARRATOR: But the mirror was destined to lie in storage for eight more years while work continued on the rest of the telescope, the science instruments, the guidance systems and the ground-based computer systems which were far from ready.

ED WEILER: At times some of us began to think it was impossible. It was a roller-coaster ride. You'd, you'd maybe take one step forward and you'd take a half step back, sometimes you'd take two steps back. That's why it took longer. It took ten years where we thought it would take four years.

NARRATOR: By the time Hubble was finally assembled its price tag was nearly $2 billion, more than twice the original estimate, but the engineers had succeeded in creating what many had thought impossible. Hubble was ready to fly.

LAUNCH VOICE: T minus 15 seconds.

JOHN TRAUGER: When it gets delivered and it's sitting there on the pad it's out of your hands completely.

LAUNCH VOICE: Ten, nine…

LAUNCH VOICE: …main engines.

LAUNCH VOICE: And we have a go for main engines start…

DUCCIO MACCHETTO: We were all behaving like children at the big event. We saw our baby being carried into orbit.

LAUNCH VOICE: …one, zero, and we have lift-off.

LOU MONTAGNINO: A strong sense of pride. A little bit of anxiety because you're watching all this go up like a roman candle.

LAUNCH VOICE: And lift off of the Space Shuttle Discovery with the Hubble Space Telescope, our window on the Universe.

LOU MONTAGNINO: Close to a decade's worth of work riding on a rocket.

ED WEILER: It slowly rises in a clear blue sky and then it went through this cloud and lit up this cloud.

JEFF HESTER: And here it was finally on its way to orbit. An incredible morning. You're not supposed to have champagne on the causeway at Kennedy Space Centre, but we did.

LAUNCH VOICE (WOMAN): There are smiles galore down here.

LAUNCH VOICE MAN: It's quite a sight.

LAUNCH VOICE WOMAN: Great work up there you guys.

NARRATOR: The world was waiting for Hubble to unlock the deepest secrets of space. (ACTUALITY CHAT) But before anyone could see so much as a single image from the telescope, the ground controllers had to spend a month testing Hubble's systems. (ACTUALITY CHAT) The scientists had to wait before they could begin solving the greatest mystery of all: the birth of the Universe. This was one of the most important debates in astronomy. Some calculations suggested the Universe was 10 billion years old, but this could not explain why many stars and galaxies seemed to be even older. Other calculations suggested the Universe was 20 billion years old, but this could not explain why there was so little evidence of stars burning out, or galaxies dying.

WENDY FREEDMAN: At the time of the launch astronomers were involved in a fierce debate so it was with great anticipation. In fact it was one of the motivations for building the Hubble Space Telescope was to get at this question: how old is the Universe?

NARRATOR: Even before Hubble was switched on astronomers knew exactly what they needed to do to find the age of the Universe. They would programme the telescope to make precise observations of many galaxies. In each one they would seek out the most accurate milestones in the Universe, single pulsating stars called Cepheid variables. Discovering the exact rate at which each Cepheid pulsated would allow astronomers to calculate precisely how far away they were and how fast their galaxies were travelling. If the team could find enough Cepheids they could measure the expansion of the Universe more accurately than ever before.

WENDY FREEDMAN: It would be the first time when we could actually measure distances to a large sample of galaxies, find these Cepheid variables and do that with very high accuracy and it just couldn't be done from the ground and the controversy had lasted for so long without an obvious way of resolving it that we couldn't help being very excited at the thought of actually getting to the, the bottom of this discrepancy.

NARRATOR: Finally, the weeks of testing were over.

CHARLES PELLERIN: We saw the power system working. the pointing and control system stabilised the telescope, the thermal system put it at the right temperatures, the telemetry system communicated with the ground, the instruments worked, the doors opened, the levers moved, everything looked great. We had a super telescope.

NARRATOR: The moment everyone was waiting for had arrived. Hubble was ready to transmit its first pictures back to Earth. But something was wrong.

JEFF HESTER: What we had expected to see in those first images were very, very sharp points of light. What we actually saw were kind of big, blurry things, in fact things that at first glance didn't look an awful lot sharper than what we could see from the ground and we looked at 'em and we thought hmmm.

NARRATOR: Initially the engineers were not worried.

TERRY FACEY: We didn't expect the telescope to be currently focused the first time. There was no expectation of that, but we knew we had alignment and focussing adjustments to do and we set about doing those, but things from the very beginning just didn't go according to plan.

CHARLES PELLERIN: We thought all we had to do is move the secondary mirror a little bit and the image would get sharper. We moved the mirror, the image got worse. We moved again, image got worse. Back, it got worse. Every place the image was worse. The telescope couldn't focus. It was unbelievable. How could the telescope not focus?

(ACTUALITY CHAT)

NARRATOR: The Hubble had a serious problem. Back on Earth, scientists were baffled. With the whole mission at stake, they had to try to fix the telescope as soon as possible.

DR. CHRISTOPHER BURROWS (European Space Agency): Some things in the telescope are easy to change out. The instruments are designed to be replaced and upgraded by astronauts. Some of the problems were problems we could have fixed perhaps just by commanding the telescope into a different operating mode, to change the way we used it, so we went into a period where we analysed those images and tried to understand what could be wrong with the telescope.

NARRATOR: They ran simulations of every possible fault with the telescope to see what could account for the blurry pictures. The answer was unthinkable: the most perfect mirror in the world was the wrong shape. Hubble's mirror had a flaw called spherical aberration. It was slightly too flat which meant that the light reflected from its edge and light from its centre were focussed in different places. It could not produce a sharp image and there was nothing anyone could do about it.

CHRISTOPHER BURROWS: Spherical aberration on the primary mirror was, was the sort of failure which could not be corrected by any way that we had planned. It was a problem that went to the heart of the science that we hoped to do with Hubble so in many ways it was a worst case scenario for the scientists and for the, the managers of the programme.

DUCCIO MACCHETTO: I personally felt like killing somebody because having invested twelve years of my life up to that point in, in this project and seeing that this was a really major disaster for us, you know the reaction is that one.

WENDY FREEDMAN: It was somewhat like being punched in the stomach and having the, the wind knocked out of you. You're all set to go and here was this terrible disaster.

TERRY FACEY: This, this was a, this was and acknowledged and acclaimed perfect mirror and suddenly it's not and that's, that's a very sudden shock and very hard to grasp and to, and to accept.

BUD RIGBY: It was shocking. I was upset by it. I, my association with the people that worked on that mirror is and that pro, that whole project is very near to me.

LOU MONTAGNINO: I think that sums it up. OK, it was disappointment certainly, OK, because it was an awful lot of time and energy put into this thing, a lot of personal commitment and a lot of technology and to have it all be tarnished was very, very disappointing.

REPORTER: Have we ended up with a situation where it was degraded science or cancelled science - which is it?

REPORTER: If this aberration was such a perfect textbook case why wasn't it caught on the ground?

NARRATION: NASA was in the firing line.

ED WEILER (speaking in archive footage): It would be dishonest of me to say the, the mood of the scientist is very happy right now. We're all frustrated obviously.

REPORTER: What are the possible things that could have happened?

REPORTER: I want to follow up on my colleague's question see how many straws there are on this camel's back.

ED WEILER (speaking in archive footage): One instrument where we have a major problem of course is the Wide Field Planetary Camera. Its prime science is going to be done in the visible portion of the spectrum. We feel right now that there's probably no real science that we can do with the Wide Field Camera at this time. And I'll stop there. ED WEILER: The Press Conference where we announced Hubble's spherical aberration was by far the worst day of my life. You know I was basically saying we messed it up. So at that point you know I was convinced the programme was dead.

CHARLES PELLERIN: People began to disintegrate. Some had to be taken out by guards to rehabilitation centres for drugs and alcohol. The astronomy community was tearing itself apart. The sense of the great involvement and great participation now became a two-edged sword. Everybody began blaming everybody about how could this have happened, how could such a mistake have been made? It was a very bad time.

NARRATOR: This was not just a disaster for NASA, it was a national scandal. Congress demanded to know what had gone wrong. A board of inquiry was quickly established, but it faced a difficult task. The mirror had been completed eight years before and the team who built it had dispersed.

INVESTIGATOR: Now are these the interferograms that you had analysed independently at Arizona?

INVESTIGATOR: No I've never had these before. I was looking for an additional set which are the refractive ones with the curve.

NARRATOR: But remarkably the original equipment used to test the mirror was still in position and it was here they discovered that unknown to anybody one tiny accident had crippled the telescope. It caused a minute fault in the null corrector that had been used to test the mirror's shape. A null corrector is a complex array of lenses and smaller mirrors. The spacing between these elements is critical. The slightest error will produce a mistake in the mirror under test. The spacing in Hubble's null corrector depended upon measuring rods like these, half a metre long and one centimetre wide. A fleck of black paint, as tiny as this, just two millimetres wide, had at some stage been chipped off the cap on one of the rods. This exposed a chink of metal. Light hitting this chink distorted the measurements causing the fatal error.

CHRISTOPHER BURROWS: And that error was not picked up and resulted in the null lens being incorrectly built. Now that error then got slavishly copied onto the primary mirror for the Hubble and as a result, the primary mirror was assumed to be correct because the null lens said it was, but in fact it was wrong.

NARRATOR: A fleck of paint, all it took to ruin the entire mission.

TERRY FACEY: Who could predict a piece of black paint would come off, who could predict that the microscope would happen to be right over that piece of shiny stainless. I mean one can envisage hundreds of ways in which that might not have happened and on this occasion it happened.

NARRATOR: In the end the mirror was only minutely misshapen, just one fiftieth of the width of a human hair, but it was enough to put the mission's goals out of reach. The Hubble had to be saved at all costs. Scientists and engineers began desperately trying to find a solution to its problem.

MAN: …which we've listed as mechanical correction or deformation.

CHRISTOPHER BURROWS: We formed a committee, a strategy panel, to come up with ideas and about 30 suggestions came up.

(ACTUALITY CHAT)

DUCCIO MACCHETTO: We put everything on the table, even the craziest idea, to see what we could do to fix the, the problem.

MAN: This is replacement of the secondary just as a straight correction.

CHRISTOPHER BURROWS: And they ranged from going up with the Shuttle, taking the spacecraft, bringing it back to Earth and replacing the primary mirror.

DUCCIO MACCHETTO: To send astronauts up and actually inside the tube of the telescope and do something to the, to the optics which was crazy but we discussed it.

MAN: …for that correction which is obtained by…

CHRISTOPHER BURROWS: There were ideas even to try to re-coat or change the shape of the primary on orbit with heaters or something like that.

DUCCIO MACCHETTO: To put a, a mirror in front of the telescope which was slightly bent so we would have the correction in it.

CHRISTOPHER BURROWS: Try to move all of the instruments back by several metres.

MAN: Shows the front end of the telescope…

MAN: …going to be a report…

MAN: I don't have a picture of that…

DUCCIO MACCHETTO: And so on and so forth and so we decided that we would not discard any idea a priori. We would write it down, we would see the pros and cons, see whether it was feasible or reasonable and only at the end we would discard it and through this process over a, a month or two we came up with the idea of what was then implemented in the Hubble Space Telescope.

NARRATOR: Among the proposals was the ingenious solution. An instrument that would match the error in the mirror in reverse and cancel it out. This optical fix was called the Corrective Optics Space Telescope Axial Replacement or COSTAR for short.

CHARLES PELLERIN: In the real telescope there would be an instrument here, an instrument here, an instrument here and the front of the telescope is this way. The light would come in, starlight would come in, hit the mirrors, become aberrated, then come through here where there's a hole in the primary mirror and reflect first off one of these mirrors into one of these. Now these are so important. These mirrors are made exactly like the primary mirror except that the imperfection is exactly inverse so once the light leaves here it's perfect light again, so the lights comes in, hits both mirrors, goes into one of these four instruments and voila, a perfect telescope.

NARRATOR: There was no way of knowing whether COSTAR would actually work, but hopes of saving the Hubble now lay with this intricate design. Plans for an ambitious repair mission began to take shape.

ARCHIVE FILM NARRATOR: In December the crew will rendezvous with the Space Telescope for the first time. The astronauts will then perform several space walks to complete the needed servicing and repairs.

NARRATOR: There would have to be five gruelling space walks, more than had ever been attempted before, to install COSTAR and a new camera and to make other essential repairs.

JEFF HESTER: They were putting in two new instruments, they were doing repairs on the gyros, they were working on the computer, they were replacing the solar arrays, they were working on the magnetometers. There was virtually no major part of the spacecraft that they were not putting their hands on.

CHARLES PELLERIN: Everybody knew what happened when we failed with Hubble the first time and everybody knew the stakes were very high. A second failure would be unforgivable.

ED WEILER: And we started reading stories of editorials and speculation by some of the major press saying hey, maybe the future of NASA depends on the success of this mission. Well there was enough pressure on us all to just do this mission but now suddenly instead of the future of Hubble, the future of your entire space programme is depending on success.

NARRATOR: Now the hopes of NASA were pinned on seven determined astronauts.

STORY MUSGRAVE (Astronaut): I mean there were words that were even such as: 'this is the measure of NASA, this mission is the measure, this, this mission defines is there a NASA? Myself, I got most of the calls you know as Payload Commander. The more pressure I get the more I dive into the details, the more I want to make this happen.

NARRATOR: The astronaut team undertook the most punishing training schedule since Apollo to make ready for this boldest of missions.

LAUNCH VOICE: Four, three, two, one, zero.

LAUNCH VOICE: And we have lift-off. Lift-off of the Space Shuttle Endeavour on an ambitious mission to service the Hubble Space Telescope.

NARRATOR: In December 1993 the impossible mission was launched.

STORY MUSGRAVE: To chase after the Hubble, to go catch it and to see something of - it's awesome. When you go off to catch that thing and it happens on the horizon it's a powerful moment. It is not any other spaceship. Hubble touches people, it touches me.

ASTRONAUT: Oh Houston we are inspired, we are ready. Let's go fix this thing.

NARRATOR: The astronauts got to work. They knew that the tiniest mistake could be catastrophic for the mission.

ASTRONAUT: Four, five, six. You've got it.

ASTRONAUT: Oh look at that baby. Beautiful spanking new WF/PC.

NARRATOR: First came the delicate task of putting in the new camera.

JOHN TRAUGER: The instrument doesn't just kind of go in. It goes in with incredible precision. What we worried about was any astronaut could just kind of bump into it and that would be the end of our mission.

NARRATOR: The astronauts eased the new camera into place.

(ACTUALITY CHAT)

ASTRONAUT: OK, looks like it's in there.

ASTRONAUT: Yeah.

NARRATOR: Later, COSTAR was manoeuvred into position with less than an inch of clearance on either side.

ASTRONAUT: Would you like to see it?

CONTROL VOICE: Good work guys.

NARRATOR: The astronauts had completed every task to perfection. Now it was over to the scientists on the ground.

ED WEILER: Then it dawned on us wait a minute, this is only half the job. Will that camera work? Will COSTAR work? Did we get the right prescription for those glasses to put on Hubble?

NARRATOR: Two weeks later it was time to put the repairs to the test. First they tried out the new camera.

JOHN TRAUGER: As usual everything on Hubble happens at night for some reason and the first images were scheduled to come down at 1am, the whole camera team were all semi-circle around the computer screen, the image slowly built and so you see bright things first and right in the centre was a very bright star. Everyone was thrilled. There were cheers. I mean it was black and white. Before we didn't know and afterwards we knew, we had it.

NARRATOR: As COSTAR and the rest of the repairs were tested it seemed the mission had been a complete success.

DUCCIO MACCHETTO: It was like day and night. I mean it was a new telescope. The things we could see right there and then were so different from the ones we had seen only a week before that we were totally amazed and we jumped up and down with joy when we saw those, those images. For me the Hubble Space Telescope was going to open a totally new window on the Universe, really blow my mind and allow me to see things that were beyond even my own wildest dreams.

NARRATOR: Now the science could begin in earnest. The Hubble could at last probe the origins of stars, galaxies and the Universe itself. Astronomers had long believed that stars formed when clouds of gas collapse onto a centre of gravity. Now by pointing the Hubble into one of these vast clouds, called the Eagle Nebula, they had a unique chance to see it actually happening. What Hubble found was a revelation.

JEFF HESTER: We fairly quickly put together those images and then we went running up and down the halls pounding on everybody's door saying, you know, you've, you've got to see what we've got and I think most of the rest of that day was spent in conversations with various people kind of gathered around out in the hall there looking at these pictures and saying boy, can you see that and you know what about this thing and, and speculating on what these images were actually showing.

NARRATOR: Astronomers saw for the very first time the spectacular places where stars are born. The Hubble revealed huge pillars of gas, trillions of miles from top to bottom. Deep within these great columns were the telltale signs of newly forming stars.

JEFF HESTER: And there are these little bitty knots in there each one of which could hold our entire Solar System and in fact inside a few of those we had good reason to believe that there were new stars forming and there for a minute you are, in the purest sense, what a scientist is, that is you are just a human being looking for the first time at some aspect of nature and experiencing the wonder and awe that that look at nature has to offer.

NARRATOR: But the Hubble's main goal was to resolve the great debate over the age of the Universe.

WENDY FREEDMAN: This project was not a matter of turning on, switching on the Hubble Space Telescope one night and, and getting an answer. It required observing many, many galaxies and going to the fields time and time and time again.

NARRATOR: From hundreds of billions of stars they had to seek out the few pulsating Cepheids they needed. If scientists could find enough of these milestones they could measure their distance and the speed of their retreating galaxies and then make precise calculations of how fast the Universe is expanding. Then, working backwards, they could determine when it began. It took over five years, but finally in May 1999 they had calculated the age of the Universe.

WENDY FREEDMAN: And the age that we determined is 12 billion years and that now appears to fit from everything else we know about the ages of stars and our own galaxy and other measurements that have made, it appears to now make a consistent story. We've been able to make a major step and it's been very exciting to be part of that endeavour, taking part in something unfolding.

NARRATOR: Some 70 years after Edwin Hubble, the space telescope had resolved the biggest question in astronomy. The Universe began around 12 billion years ago. At last its beginning seemed to fit with everything known about the birth and death of the stars within it. Now they know when it began, astronomers are seeking to understand how the Universe evolved into a vast array of intricate galaxies. Before the Hubble, no telescope could look back to the beginning 12 billion years ago to find the answer. Theory suggested that the Universe evolved slowly and that it took billions of years for the first galaxies to form. These ideas could be tested for the first time in a remarkable observation called Hubble Deep Field. The Hubble was pointed at one seemingly bland patch of sky for ten days, long enough to try to detect the first faint light from the beginning of time. Nobody knew what it might reveal.

JOHN TRAUGER: We literally took the Hubble Telescope to its limit. It was a wonderful example of just seeing how far we could go. The idea behind it was to look in a part of the sky that was not obscured by known objects like stars in our own galaxy, to just look at the texture of the background sky and what would we see.

NARRATOR: In this blank patch of sky the Hubble unveiled a spectacular view. Galaxies never seen before that were nearly as old as the Universe itself.

JOHN TRAUGER: About 4,000 galaxies are seen in that one piece of sky that's about as big as a grain of sand at arm's length and, and there isn't much else which is to say that we are seeing the first glimmerings, the first light from the first stars in the Universe.

NARRATOR: What astonished the astronomers was that these galaxies were already fully formed.

ED WEILER: We didn't see galaxies being born. We saw well formed galaxies. This was not expected. This showed us that we're not looking far enough back, we're not looking far enough into space, We instead of seeing the babies being born we saw one year olds, two year olds, ten year olds. We didn't see the one day olds, the one hour olds, the one second olds, so to speak. Quite a surprise.

NARRATOR: How could such perfectly formed galaxies exist so soon after the Universe began? This is one of many mysteries that the Hubble has revealed, but cannot solve.

WENDY FREEDMAN: There's a period that astronomers refer to as the Dark Ages. We know nothing about that time, anything, when galaxies were actually assembling and forming and there's a new telescope that will go, go up which is now being referred to as the next generation space telescope to follow the Hubble Space Telescope where we will actually begin to probe those Dark Ages, we'll actually be able to see galaxies as they're assembling and as they're forming and how they're changing over time.

NARRATOR: Even more ambitious than the Hubble, the next generation space telescope is already in development.

TERRY FACEY: So this is the concept for the next generation space telescope in which we're proposing an 8 metre diameter mirror, much larger than the 2.4m of Hubble Space Telescope and in order to, in order to package it into available launch vehicles this 8m mirror has to fold up and, and so it'll be built in eight segments. These mirrors are very thin. They need to latch so that this mirror and this mirror are correctly aligned to within a very small fraction of a micrometer and that is, that is an enormous challenge, so it's, it's, it's in many respects more risky certainly. It has to be inherently more reliable, but the pay-off is we'll get much more science.

DUCCIO MACCHETTO: We'll operate a large distance from Earth. We need to put it far from Earth because even the heat from the Earth will be too much. It would heat the, the mirrors and so we're putting it in a place which is over a million kilometres from the Earth and we'll have to operate it remotely for many, many years.

INTERVIEWER: Are you confident it's going to work?

TERRY FACEY: I'm as confident that this will work as we all were that Hubble Space Telescope would work a decade or so before its launch. Yes, it'll work. I'm not confident, I wouldn't predict you a launch date, I won't predict for you what it'll cost, but it will work, eventually.

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