This 16,000-word article first appeared in Discover magazine in 1985, in a much shorter form. Four years later, it was condensed for publication in Reader's Digest. What follows is the original, uncut manuscript, updated to reflect developments in the period since.

The Big Glass

By Terry Dunkle

I. The Pursuit of Smoothness

One afternoon in the fall of 1981, two dozen men in ice-blue jumpsuits, wearing surgical masks, stood in a cavernous room in a factory in Wilton, Connecticut, at the foot of a two-story canister whose interior was being pumped to a vacuum nearly as empty as interplanetary space. Inside was an eight-foot-diameter glass disk, worth $15 million, which Jack Kurdock and his crew were about to coat with aluminum. It was said to be the most perfectly crafted object that human beings had ever made: the primary mirror for the Hubble Telescope, a $2-billion observatory planned for installation in earth orbit. Five years of nerve-wracking labor had gone into grinding and polishing the big glass. Now, in a five-minute operation which he had been planning for years, Kurdock was going to give the mirror its final touch. Never in his 37 years had he felt so nervous. If he failed, his company stood to lose millions in aerospace contracts. If he succeeded, scientists would soon be able to see almost to the beginning of the universe.

The universe is thought to have exploded into being more than ten billion years ago from a cosmic “egg,” a frightfully dense globe of energy, perhaps smaller than the head of a pin. It is still expanding. If we could see the details of its birth, say astronomers, we could run the explosion forward in time and predict how the universe will end—whether it will peter out into a vast, cold nothingness or, as some believe, collapse and be born again.

Anyone can see partway to the beginning with the naked eye. In the constellation Andromeda, almost straight overhead around midnight each fall, lies the farthest object the naked eye can see: a faint smudge of light resembling a fuzzy star. It is actually a whirlpool of billions of stars, a near twin to our Milky Way. Because its light has taken two million years to reach us, we see the Andromeda galaxy as it was two million years ago.

Two million light-years isn't far. The Hale Telescope on Mount Palomar, California, collecting light with a 200-inch-diameter mirror, has photographed galaxies a thousand times more remote. But even these are relatively nearby. To reach the Big Bang itself, we need to probe at least five times their distance, perhaps ten.

The Palomar telescope would reach a lot farther if it weren't sitting under 100 miles of air. Almost half the starlight entering our atmosphere is absorbed by dust. Another fraction is lost in the glow of city lights, which pollute the darkness even at the most isolated observatories.

Still more light is wasted by atmospheric turbulence, which causes the stars to twinkle. Magnified in the Palomar telescope, a twinkling star appears to dance and swell like a dime lying on the bottom of a swimming pool. If it is very faint, it smears itself too thinly to register on even the most sensitive cameras.

The greatest loss, however, is the fraction of light at the ultraviolet end of the spectrum, where galaxies shine their brightest and deliver the most information. Since ultraviolet light can focus more sharply than other wavelengths, it has the potential to show the universe in incredibly rich detail. Unfortunately, the atmosphere blocks it almost entirely.

The man who first dreamed of the Hubble Telescope was Lyman G. Spitzer, of Princeton University, who in the mid 1960s began urging NASA to station a 120-inch telescope in orbit above the atmosphere. Such an instrument would reach ten times farther than Palomar's, easily approaching the Big Bang. It would also reveal objects in fifteen times sharper detail. Nearby stars—mere points in the most powerful telescopes today—would show up as disks, perhaps mottled with spots, like the sun. They might even turn out to have planets. If they did, the chances of our having company in the universe would increase many fold.

As the years passed, Spitzer and his colleagues described even deeper mysteries the telescope might solve. One is the riddle of quasars—blue pinpoints of light, farther removed than any known galaxy, which some-how release more energy in a single second than the sun does in a million years. In theory, a chunk of quasar the size of a marble could power our civilization for centuries.

“Some of us think quasars are galaxies just being born, or perhaps an earlier generation in its death throes,” said John Bahcall, a cosmologist at the Institute for Advanced Studies, in Princeton, New Jersey. “If we're right, every quasar ought to be surrounded with a dim 'fuzz,' like the Andromeda galaxy. The trouble is, the fuzz is too faint to show in earth-bound telescopes. The Hubble Telescope should bring it up loud and clear.”

The most profound question the telescope might answer is how long the universe will last. In theory, that depends on how much matter there is. If the universe is bulky enough, its gravity should eventually halt the grand explosion and pull everything back into a point—from which a new universe may explode. So far, astronomers have located only a tenth of the matter needed for this to happen. Some conclude that the universe will go on expanding forever, growing thinner and cooler until the last galaxies fade and the cosmos is plunged into eternal darkness. Others imagine that we have simply missed huge quantities of hidden matter—dust clouds, perhaps, or the infinitely dense and invisible “black holes.”

It should be easy to detect hidden matter. “We need only study the motions of individual stars in a large sampling of galaxies, looking for the extra speed the dark objects would induce in them,” explains Spitzer. But earthbound telescopes can pick out individual stars only in the nearest two dozen galaxies. The Hubble Telescope will be able to do so in tens of thousands.

“These are only a few of the things we know the telescope will see,” concludes Spitzer. “The most exciting are likely to be those we can't even imagine today. Quasars, you know, were unheard of before the two-hundred-inch at Palomar. Before Edwin Hubble's work with the one-hundred inch on Mount Wilson—only seventy years ago—most people thought the Milky Way was the whole universe. The Hubble represents a bigger leap in performance than either of these—a leap just as great, in fact, as Galileo's first telescope. The Space Telescope will unlock the universe the way the microscope unlocked the cell.”

In essence, the Hubble Telescope's design was very simple. At its heart would be a 120-inch primary mirror, shaped like a pineapple ring, with a 24-inch hole in the middle. Incoming starlight would fall on its subtly dished face, bounce to a 13-inch secondary mirror in the front of the telescope, and be thrown back through the primary's hole into a bank of electronic cameras. Everything else in the system was designed for pointing the telescope, holding it steady, and transmitting the pictures to earth.

Unfortunately for the thousands of astronomers who wanted to use it, the telescope ended up smaller than expected. In 1976, as NASA was preparing to award contracts, a budget fight in Congress forced a reduction to 94 inches. “It was a terrible blow,” says Bahcall. The down-sized mirror would collect 36 percent less light, causing the instrument to fall short of the Big Bang by as much as six billion light-years. The reduction would also jeopardize the search for extrasolar planets, a marginal undertaking even for a 120-inch. And the volume of space that could be searched for hidden matter would shrink to only a third of what astronomers had planned.

In theory, part of the loss could be made up with a more accurate mirror. A telescope's power rests on its ability to focus the light it collects into a tiny point. If the glass could be polished to an unusual smoothness, fewer light rays would be scattered outside the point, significantly increasing the contrast and brightness.

The specifications already called for a mirror ten times more accurate than Palomar's. The main specification was “Lambda by 64,” meaning a surface accuracy of one sixty-fourth the wavelength of neon light, or half a millionth of an inch. Blown up to the diameter of the Gulf of Mexico, such a mirror could have waves averaging no more than a quarter of an inch in height. (A typical eyeglass lens at that scale might have 50-foot swells.) Meeting the specs would be almost impossible, let alone exceeding them.

The Lockheed Spacecraft and Missiles Corporation won the contract for the spacecraft as a whole, while two other companies competed for the Optical Telescope Assembly, or OTA—the part containing the mirror. These were Eastman Kodak and the Perkin-Elmer Corporation.

Perkin-Elmer wanted the contract badly. Although its optical division had made a few mirrors for smaller space telescopes in the sixties and early seventies, including the 36-inch Copernicus orbiter, the company was known primarily as a manufacturer of laboratory instruments, mini-computers, and machines for printing computer chips. It saw the OTA as a stepping stone to more lucrative projects.

In particular, Perkin-Elmer had its eye on the Solar Optical Telescope (SOT), a $60-million orbiter NASA planned to launch four years after the Hubble. “We'd like very much to build SOT,” said Perkin-Elmer president Horace McDonell. “It'll prove we can handle an entire spacecraft on our own.”

With SOT under its belt, McDonell thought his company might win a contract for the Advanced X-Ray Astrophysical Facility, to be launched in the 1990s. Then it could make a play for the Large Deployable Reflector, a 1200-inch colossus to be unfolded in orbit by the year 2000. “We'll be the Lockheed of the twenty-first century,” boasted one employee.

Perkin-Elmer had a few spots on its record, however. In 1968, a technician had tripped over a piece of scrap lumber while helping to carry the Copernicus mirror. The accident had destroyed the mirror—worth a million dollars at that stage—and seriously threatened the spacecraft's production schedule. More recently, Jack Kurdock's crew had forgotten to throw a switch while coating a mirror for the Einstein X-Ray Observatory, forcing a major optical component to be re-ground.

But the darkest blot had occurred shortly before the bidding for the OTA. To prove its mettle for large optics, Perkin-Elmer had sunk a million dollars in NASA funds into polishing a 60-inch-diameter test mirror. “The thing turned out okay in the end,” says a source close to the work, “but at the time we submitted our proposal it looked like a total abortion. They had scratched it, and turned the edge so badly it looked like the heel of an old shoe.”

To counter these shortcomings, Perkin-Elmer tried a clever stratagem. NASA was planning to ask whoever built the OTA to subcontract a spare mirror, in case the flight mirror was broken or failed to meet spec. Shrewdly, Perkin-Elmer named its competitor—Eastman Kodak—as its sub. Having thus calmed NASA's fears about the mirror, it swung an army of engineers into outdoing Kodak's proposal for the rest of the OTA.

The engineers did their homework brilliantly. They dummied an 18-foot tube that could orbit from the sunlit to the shadowed side of the earth without shrinking more than 150 millionths of an inch. They designed sensors that could lock the telescope onto a target as small as a fly at 170 miles. They devised camera mounts that would allow space-walking astronauts to remove outdated cameras and slide in new ones. And they worked especially hard on their estimates. On Bidding Day, they declared they could build the OTA for less than $70 million.

“They had a superior technical proposal and a very attractive price tag,” recalls James M. Beggs, then head of NASA. On July 31, 1977, his agency awarded Perkin-Elmer the OTA contract. But the agreement carried a proviso: If Perkin-Elmer's mirror ended up inferior to Kodak's, the “spare” might be put in the telescope instead.

“From that day on,” said one of Perkin-Elmer's 5,000 employees, “the word around here was, 'Our mirror must fly.'”

To head its mirror team, Perkin-Elmer chose 47-year-old Ronald Roland Rigby III, also known as “R-Cubed” or “Bud.” Rigby was a veteran of the company's Electro-Optical Division, which manufactured the world's largest-selling machine for printing computer chips. Called the Micralign, the machine worked like a souped-up slide projector, using a highly accurate 20-inch mirror to focus pictures of electrical circuits onto silicon wafers. Rigby already knew how to meet Hubble Telescope specs on areas the size of a man's hand, and had 25 years of experience in larger, less accurate mirrors used in spy satellites.

“Bud was also one of the few optical engineers in the company who could stand the stress,” said a manager above him. “He's not an introvert, like most of these glass people. Put them on a job like this and they go to pieces. Remember Bernhard Schmidt?”

Schmidt, the brooding genius who polished the 100-inch mirror that Edwin Hubble used, was reputedly driven insane by the task.

“Bud's already insane,” declared one of the hundreds who worked on Perkin-Elmer's mirror, “so it didn't make any difference.”

Rigby, a florid-faced Irishman with a pushed-up nose, green eyes, and yellowish-white hair, took several members of his polishing team to lunch with a reporter one day shortly after delivering the finished glass to Kurdock for coating. “Gimme a Baconburger, well done,” he told the waitress. He made a pistol of his right hand and pointed it at her. “And I mean well. W, W, W. If it tastes like a manhole cover, it's just right.” He shut the menu and gave it to her.

“We call him Prince Charming,” said Lou Montagnino, a big, flawlessly groomed man wearing designer glasses.

“Christ, it's hot in here,” said Rigby, taking off his suitcoat. Underneath was a white two-pocket shirt with both pockets bulging with pens, pencils, rulers, a sleeve of Maalox tablets, a pack of True Menthols, a calculator, a checkbook, and a plastic case for his eyeglasses, which at that moment were resting on top of his head. “Where was I?”

“Difficulty of making the mirror,” said Jim Smith, a wiry man with slicked-back hair.

“Listen,” Rigby said to the interviewer. “There isn't one of us on this team whose whole life—whose personal life, okay?—hasn't been seriously impacted by the making of this optic. Lou? Smitty?”

The others nodded.

Most of the team had worked on the project for years before the polishing even began. First they had to oversee manufacturing of the mirror blank at Corning Glass. To save launch weight, the blank was cast not as a solid disk, but as two thin plates sandwiching an “egg-crate” interior made of slender glass slats. It was 90-percent air.

The mirror's front plate—the one that Rigby would shape and Kurdock would give its reflective coating—was molded to approximately the right curve, a concave figure called a hyperboloid. Using spinning disks and powdered abrasives, Rigby's team then ground away most of the irregularities left by the mold, producing a satiny surface that would later be polished to fit the curve exactly. From casting to fine-grinding, this preliminary work lasted more than two years.

Meanwhile, the team wrestled with the problem of supporting the blank so that it wouldn't sag under its own weight (nearly a ton) during the polishing. If it sagged by even a millionth of an inch, the mirror would relax into a different shape in the weightlessness of space. “You'd get star images like big, fuzzy cotton balls,” Rigby explained.

For a time, the team considered laying the blank on a greased rubber bladder, trusting the air inside the bladder to equalize the pressure at all points. This would be elegant and cheap, but it provided no way of monitoring the forces on the mirror's back—of knowing for certain that the rubber wasn't binding or stretching somewhere. So instead, the engineers devised a “bed of nails” with 134 titanium push-rods, each bearing on a sapphire glued to the mirror's back, and each slung on a delicate leaf spring that could be adjusted as finely as a pharmacist's scale. On this device the mirror would float almost as freely as it would in orbit. Cost: $2 million.

An even bigger problem was finding a way to gauge the mirror's accuracy. After each step in the polishing, the team needed to know precisely where and how much the surface deviated from the ideal hyperboloid, so they could design the next polishing run. Montagnino solved the problem (or so everyone thought) with a $5-million device that shone a pair of laser beams on the surface, producing a pattern of dark, wavy interference bands like those seen in a pair of overlapping windowscreens.

By analyzing these “interferograms” with a computer, Montagnino was able to generate contour maps showing bumps and hollows as shallow as ten billionths of an inch. So sensitive was the device that traffic on Route 7, half a mile from Perkin-Elmer's polishing plant, shook the basement too violently to permit measurements except in the wee hours of the morning. “We had to polish all day and measure all night,” said Rigby.

The physical stress was nothing compared with the mental, however. “It's one thing to do a good job,” explained Smith. “It's another thing to have to do a good job, and it's still another to have to do it with people standing over you all the time.”

“Amen,” said Rigby.

“Like the Teacup,” said Montagnino.

“Oh, Jesus,” said Rigby, “let's not get into that.”

The Teacup Affair was one of the most frightening in Perkin-Elmer's forty-year history. It began during a routine inspection one morning late in the fine grinding, when an inspector smeared kerosene on the frosty surface of the mirror to look inside. Just beneath the surface, not far from the mirror's edge, he found a tiny crack radiating white leaders into a shape like the bowl of a teacup, one-quarter inch high.

Panic ensued. In a really large piece of glass, the tiniest nick or chip can spell disaster, because large forces bottled up inside always concentrate at the sharpest point. Mirrors smaller than this had been known to shatter at the touch of a finger, a slight temperature change, or even a loud noise. A few had burst while opticians were home in bed sleeping. Unless the Teacup were removed and the wound safely rounded, the crack might begin to grow.

An argument broke out between Rigby's group and other engineers on the project. Rigby wanted to cut into the mirror's flank with a dental drill, angle the drill upward, and clean out the Teacup from below. Bill Swanson, a stress analyst charged with predicting whether the mirror could survive a Space Shuttle launch, complained that the repair hole's irregular shape would make the mathematics too difficult and unreliable. His group preferred lifting out the Teacup with a coring tool, coming in through the front.

“Our mirror is not going to have a hole in its face!” protested some of Perkin-Elmer's top managers.

“That's not the point,” Rigby told them. “A hole that small won't affect the telescope's light-gathering power. The real problem is, the pressure on the coring tool will be adding a force in the same direction the crack wants to grow. If one of those leaders opens up, it's going to run all over the place. I work with glass. I know.”

“The leaders are sealed,” replied one of those in the coring camp.

“You don't know that. I don't know that,” said Rigby.

The leaders would be sealed only if the crack had developed at Corning Glass before the mirror blank's final cooling. Nobody was sure it had.

For the moment, Rigby seemed to have the upper hand. Then someone realized that drilling through the side of the mirror would pollute its interior with glass dust. The “egg crate” had 144 cells, each larger than a half-gallon milk carton, communicating with one another through a single quarter-inch hole in each cell wall. Wash water would drain out of the mirror about as readily as from a Tabasco bottle. In space, leftover dust grains might float into the telescope's optical path, scattering light and seriously harming the image contrast. Coring, it seemed, was the only alternative.

So it happened that, after three weeks of fearing a disaster, Rigby's group found themselves doing the one thing they knew might bring one on. They held their breath as the spinning tool touched down, and gritted their teeth as it chewed its way into the glass. But the earsplitting crash they expected to hear never came.

Afterwards, the Teacup, in a frosty-sided plug the size of a ketchup-bottle cap, was sent to NASA's Marshall Space Flight Center, in Hunstville, Alabama, for analysis. Months later, word came back that the crack's leaders were thoroughly sealed; the Teacup could have remained safely in the glass after all.

The unnecessary hole was especially galling to those who had argued against it—except for Rigby. By then, he was too engrossed in the polishing to worry about anything else. The polishing stage, when the mirror's face would be smoothed into its final shape, was by far the most critical and the main reason Rigby had been called in. “Forget the Teacup!” he told his team. “By the time we're finished, it'll be like a mole on the shoulder of a beautiful woman: Who cares?”

Mirror polishing, although it has been practiced since 1712, when Isaac Newton invented the reflector telescope, is still mainly an art. The standard tool is a glass disk, about the size of the mirror, coated with pitch embedded with jeweler's rouge. Rubbed back and forth on the mirror, it polishes faster in some zones than others, depending on the length and path of the stroke.

The chief difficulty is that each type of stroke has multiple effects. A long W-shaped stroke, for example, will scoop out the middle nicely, but not without also wearing down the very edge. The optician can switch to a smaller tool, for localized polishing, but then he runs into a different problem: that of a cabinetmaker trying to sand a table top with his pinkie instead of a block. No matter how hard he tries to work the zones evenly, he ends up getting little bumps and hollows all over the place, and must return to the large tool for a “smoothing run.”

For these reasons, the optician who can drive a large mirror directly toward his goal is regarded as something of a wizard. “There probably aren't twenty people in the world who could even attempt a mirror like this,” Rigby said.

The demand for such work was rapidly growing, however. Perkin-Elmer was turning out forty chip-printing mirrors a month, as well as untold numbers of large optical windows for military jets and missiles. And the Department of Defense was planning a new generation of high-performance spy satellites, whose giant mirrors would have to be almost as accurate as the Hubble's. “Part of our mission,” said Rigby, “was to turn the art into a science.”

Rigby's group had figured out a way to use the “pinkie” method and get away with it. Their polishing machine, controlled by a computer reading Montagnino's contour maps, drove a spinning, poker-chip-sized tool over the surface of the glass, varying the dwell time in harmony with the rolling of the hills. In theory, this sure-fingered robot could whip a mirror into shape much faster than the Newtonian method. Rigby's team began using it at the very start of polishing, in August 1980.

Indeed, the robot worked beautifully at first. At the end of each polishing run, lasting several hours to a couple of days, Montagnino's interferograms showed a surface much closer to the perfect hyperboloid. But by November, as the runs grew shorter and the remaining hills more subtle, the vagaries of pitch and polishing compound began to play a larger role in the outcome. Surprises kept popping up: a deep, arcing canyon in the third and fourth quadrants, a turned edge, a mysterious scratch, a little knoll that shifted, unaccountably, from run to run. Progress slowed. “We had to adopt the carpenter's adage: 'Measure twice; cut once,'” said Rigby. “It was horrible. Work all day, work all night—”

“—and then be at your desk the next morning to explain why we weren't finished,” said Smith.

By mid November, Perkin-Elmer's top managers were under intense pressure from NASA. Ronald Reagan had just been elected President, deep budget cuts were predicted, and the Hubble Telescope was gaining a spendthrift's reputation in the press. Four years into the program, the cost estimate had risen from $435 million to $1.1 billion, and yet not a single major component had actually been built.

The reason was largely managerial: NASA had taken the unprecedented step of assigning no contractor overall responsibility for the telescope. Lockheed had been charged with integrating all the major components, but it functioned as a coordinator, not an enforcer. Time after time, components had to be redesigned because changes made by one of the dozens of subcontractors were poorly communicated to others. And with double-digit inflation prevailing in this period, every delay hurt the budget severely.

A master optician can't be hurried, however. He needs time to hone his intuition, to try his hunches—even, in Rigby's case, to pray. Rigby did not take kindly to pressure from management, particularly when it came from people who were ignorant of the details.

“I thought this polishing was supposed to be automatic,” a high-level manager said to Rigby at a low point in December 1980. “Can't you speed it up?”

“Get off our backs!” replied Rigby. “If you'd leave us alone, we could probably finish in half the time.”

Another thing that worried the managers was Eastman Kodak. Its mirror, being polished by the Newtonian method, seemed to be coming along nicely, and in fact was ahead of Perkin-Elmer's. Although Kodak's was intended as a spare, there was a real possibility, given the current fiscal climate, that if Kodak finished first, NASA would order its mirror coated and flown in the telescope instead.

Late in December, word came that Kodak had indeed reached spec. Some members of the Perkin-Elmer team panicked, but not Rigby. “Kodak's test results hadn't been confirmed,” he told me. “And when we checked, sure enough, we discovered their method wasn't sampling all the error on the surface.”

Not only was Kodak's mirror far from spec, but its test method required so much revision that NASA decided to put the mirror on hold for a while. Suddenly, Rigby had the field to himself.

As winter deepened, however, his team's progress became painfully slow. Sometimes they took more than a week to remove a millionth of an inch of glass. Nevertheless, Perkin-Elmer's management began holding out hope that the mirror would be finished by April. That was the month they would present Perkin-Elmer's bid for the Solar Optical Telescope. They needed all the impressive feats they could muster for that occasion. “Our chief competitor is Hughes Aerospace, in California,” explained one employee. “Guess who else is from California!” He meant President Reagan.

In February, Rigby faced an excruciating dilemma. The mirror's overall shape, called the “figure,” was nearly perfect: all it needed was a bit of edge work with the smallest of tools. A single polishing run might bring it within spec. But superimposed on the figure were tiny peaks and valleys that had to be brought within their own, separate spec called the “smoothness” factor. This, too, could be done in a single run—but only with a large tool and a different stroke. “The question was, should we smooth first, or go for the figure and smooth later?” said Rigby.

Rigby's decision was partly political. He was afraid that if he perfected the figure first, NASA would order the mirror coated without a final smoothing run. There was some justification for this. Everyone agreed that greater smoothness would yield sharper images in the ultraviolet—by far the most important part of the spectrum for this telescope. But nobody knew how smooth was smooth enough. There was a point beyond which further smoothing would no longer improve the image, but the math required to find that point was too complex for even the most powerful computers.

Although some people thought the smoothness spec could be safely relaxed, Rigby preferred keeping it where it was. Part of his motive was personal. The son of a gas-station owner in a steel town near Pittsburgh, he had spent thirty years climbing to the top of his profession and wanted to stay there a good long time. He knew he would never see another mirror as challenging as this one. He decided on a smoothing run.

“So we smoothed it,” he said wryly, “and what we did was, we wrecked the figure.”

The smoothing run had so flattened the edge that extra runs would be needed to scoop the middle zones to the right depth again. The correction would take weeks, maybe months, and cost up to a million more dollars. Total expenditures on the mirror, originally forecast at $6 million, had already passed the $12-million mark. NASA was appalled.

Rigby's superiors began to consider taking the mirror away from him before he reached spec. NASA was allowed to accept Lambda by 50, instead of Lambda by 64, because the more stringent number had never been guaranteed to astronomers. The only thing standing in the way of relaxing the spec was Rigby's contract with his employers, which specified Lambda by 64. In mid March, they approached him about this.

“I told them I wasn't violating my contract,” said Rigby. “And I reminded them that we had a performance premium on our contract with NASA. We'd get extra money if the telescope performed better than expected. It wasn't chicken feed, either—it was millions.

“So they said, 'All right, you can have another polishing run.'

“And we took another run, and the mirror still wasn't finished.

“'Please stop,' they said.

“And I said, 'Sign a paper absolving me of my contract!' But nobody would sign. 'All right,' they would say, 'take another run. But you're gonna be finished tomorrow!'

“This went on for weeks. By the time we finally finished—on April fourteenth—we'd made such skunks of ourselves that hardly anyone would speak to us.

“We ended up with one hell of a mirror, though. You're gonna live a good many lifetimes before you see another one like it.”

It was indeed a very good mirror. In June, NASA's chief telescope scientist for the project, William Fastie, of Johns Hopkins University, in Baltimore, pronounced the big glass “easily the finest mirror ever made.” Its overall accuracy was Lambda by 78—twenty-percent better than planned. And the smoothness factor was an incredible Lambda by 320—so fine that only a few atoms, here and there, separated it from perfection. Never before had anyone made such a large object so flawless. On the scale of the Gulf of Mexico, the glass would have wavelets less than a millimeter high. “There's no doubt in my mind that we're going to see perfect star images very deep into the ultraviolet,” concluded Fastie. “Thanks to Rigby, we'll be able to reach hundreds of millions of light-years farther than we expected.”

Rigby's worries weren't over, however. Although he had just finished the most exquisite piece of glass in the history of optics, it still wasn't a mirror. The rest of the job had fallen to a very different sort of man: Jack Kurdock.

II. A Quest for Brilliance

Kurdock had never taken the mirror quite as seriously as Rigby did. “I've got other things to worry about,” he told me one morning early in September 1981. We were sitting on the unopened mirror crate, a large wooden box bearing a number of empty coffee cups and a red tag reading NASA—CRITICAL HARDWARE. Kurdock, a broad-faced, brown-suited young man with rust-colored hair, was head of the Coating Department in Perkin-Elmer's Optical Operations Division. His chief responsibility was coating the 20-inch mirrors that went into the company's Micralign chip-printing machines. Because of the recent boom in the microcomputer industry, his workload had become frightfully heavy. “The guys in Production are throwing glass at me faster than I can coat it,” he said. “I'm already six months behind.” He frankly confessed that his main interest in the Hubble Telescope had been the excuse it provided—and the $1.5 million in NASA funds—to build the world's largest vacuum coating chamber. “I can fit six Micralign mirrors in there at once, as soon as I get rid of this baby,” he said, knocking on the wooden crate. “Want to see the chamber?”

He led the way across the room to a gleaming steel canister, sixteen feet tall and nearly as broad as a house. Its walls were four inches thick, he said. We climbed three iron steps to the entrance. A rubber gasket went pfup! as he opened the quarter-ton door.

The interior was gloomy, lit mainly by a large, open slot near the ceiling. “That's where the mirror will come in,” said Kurdock, his voice echoing. On the ceiling was a giant, toothed metal ring, from whose center, he said, the mirror would hang face-down. Near the floor, spaced evenly around the circumference, were eight copper pans about the size of pop-bottle caps. “Those are the crucibles,” he explained. Each crucible sat on a metal box attached to the wall and trailing an electrical cable. The boxes, he said, were “electron guns.”

He described briefly how the coating would proceed. After the mirror was installed in the chamber, the door and the entry slot would be sealed, and for three days a set of powerful pumps would exhaust the interior to a pressure 1,000 times lower than the telescope would experience in space. (So strong would be this vacuum that if the walls imploded, the force could equal that of three sticks of dynamite.) On Coating Day, Kurdock's team would first start the mirror rotating slowly, to help insure a uniform coating thickness. Then, at the appointed hour, half of the guns would begin shooting streams of high-voltage electrons at lumps of 99.99999-percent-pure aluminum sitting in the crucibles. As the aluminum vaporized, its atoms, unobstructed by air, would streak toward the ceiling and cling to the glass. If the guns, the rotation, and the vacuum held steady, in about three minutes the glass would gain a brilliant veneer that exactly reproduced the underlying shape and smoothness achieved by Rigby. Finally, the film would be sealed against oxidation by a transparent overcoating of magnesium fluoride (the same compound used in camera-lens coatings), to be applied by the remaining four guns. The overcoating would take about a minute and a half. When it was over, the Hubble Telescope mirror would be complete—provided it passed all of NASA's tests.

The specifications for this coating were the most demanding Kurdock had ever faced. First, it had to be incredibly thin: three millionths of an inch of aluminum and one millionth of an inch of magnesium fluoride. This was 20,0000 times thinner than a spider web—so thin that if the coating were peeled off and flung into the air, it would remain suspended for days, like smoke. Second, it had to be uniform in thickness, to within three per-cent. And finally, it had to be almost impossibly bright—especially in the ultraviolet, where the telescope would make its most important observations. “It's got to reflect at least seventy percent of the light in the UV,” said Kurdock. “I don't know of anyone who's ever done that with aluminum. Theoretically perfect is only eighty-four percent. We've been practicing on small mirrors for months, and we still haven't gotten above sixty-seven percent.”

Kurdock's biggest difficulty lay with the electron guns. In order to achieve the desired brilliance, the guns had to vaporize the coating materials rapidly and steadily. Speed was required because even the deepest vacuum would still contain quadrillions of oxygen atoms. “These are attacking the aluminum at the same time you're laying it down,” explained Kurdock. “If you don't get the aluminum on quickly and seal it up right away with the mag fluoride, you'll end up with a layer of aluminum oxide on the coating. It may be only a couple of molecules thick; you'll never notice it in visual light, but in the ultraviolet the mirror will be as black as fresh asphalt.”

Steadiness, too, was important, especially in the sealing stage. Because of a special property of magnesium fluoride, the overcoating could actually enhance the reflectance—but only if it were exactly the right thickness. A sudden drop or surge in a gun's output could leave a “dark” spot on the mirror, reducing its overall brilliance.

Although Kurdock's team had been working on the guns for months, he was still having trouble with their speed and their steadiness. Each gun's output was regulated by a sensor which monitored the evaporation rate and continually adjusted the electrical input to keep the rate constant. The input came from a quartet of 1,200-watt power supplies in a control panel outside the chamber. During practice runs, the power supplies had a habit of “slumping”: Their output would climb past a critical point, boil the cooling water in the guns, and suddenly drop to zero. The result was an inferior coating, a burned-out gun, and great puzzlement on the part of the coating team. Neither the team nor the manufacturer of the power supplies could figure out what was wrong. The slumping had happened less frequently after parts of each unit were replaced, and in recent days there had been no slumping at all, but Kurdock still worried. “We've got to have six perfect test runs in a row before we're allowed to coat,” he explained. “So far, we haven't made it past three. And they want us to coat in eight weeks!”

By “they” Kurdock meant both NASA and Perkin-Elmer, who, for different reasons, now wanted the mirror finished by the end of October. The mirror was already a year behind schedule. NASA feared that if the completion date slipped any further, the telescope would be launched too late to perform two politically sensitive missions: taking closeups of Halley's Comet before Soviet, Japanese, and European space probes reached it in 1985, and helping Voyager II chart a safe path among the moons of Uranus in 1986.

Perkin-Elmer's worry was more immediate: The company would be defending its bid for the Solar Optical Telescope before a NASA panel in November, and its top managers wanted to go into the meeting having passed the first major milestone in the Hubble Telescope program: completion of the primary mirror.

Certifying the guns wasn't the only job standing between Kurdock and Coating Day. He also had to convince NASA that his team could safely open the crate and begin handling the mirror. Moving it from the box to the chamber was a major problem in itself, the subject of many years of thought and engineering. What made it difficult was that the glass had to be washed before the coating. If the surface bore even the tiniest trace of dust, soap, or grease—a single thumb-print, say—the foreign matter would vaporize in the chamber and precoat the glass with a thin film of hydrocarbon molecules. These would have the same effect as oxidation: a coating nearly dead-black in the ultraviolet.

The easiest way to ensure that no impurities were left on the mirror was to stand it up and rinse it with distilled water until the surface began draining in perfect sheets. (“Just like in the Cascade commercial,” said Kurdock.) But the mirror was too heavy to stand on its edge; it would crack immediately, and might even shatter.

Foreseeing this dilemma, Perkin-Elmer had designed the mirror to be hung by three toggle bolts passing all the way through it from front to back. (The bolts wouldn't show in the telescope's field of view for the same reason that dust specks on a camera lens do not show in the picture: they're too close to the camera to be brought into focus.) The heads of the bolts would bear all the weight when the mirror hung face-down; their shafts would bear most of the weight when it hung vertically. The rest of the weight would bear on the inside of a $1-million “space frame,” made of welded steel tubing, which would fit over the mirror like an upside-down-cake pan. Thus distributed, the forces would neither crack the mirror nor craze its delicate film when the coating was complete.

Before the coating could begin, then, Kurdock's team had to unpack the mirror, slip the space frame over it, bolt the two together, turn the resulting assembly on edge, wash it, dry it, turn it face-down again, lift it onto the trestle leading into the chamber slot, and finally draw it safely inside.

None of these operations could be done in a hurry. The simplest mistake—dropping a nut or a screw at the wrong moment, or losing one's grip on a wrench—might crack the glass and force Perkin-Elmer to coat the now-finished Kodak mirror instead. To guard against such accidents, every one of the 1,500 steps in Kurdock's job had been meticulously planned and written up in a special book, Volume 5088, which the team was expected to study and obey as a fundamentalist obeys his Bible. The book was two inches thick, and in places devoted whole paragraphs to the tightening of a single bolt. To make sure it was followed to the letter, every step had to be performed under the watchful eyes of two quality-assurance inspectors, one from the government and one from Perkin-Elmer.

“Those quality guys can really make your life miserable,” said Kurdock. “Professional nit-pickers, is what they are. They report to no one, they don't have to justify the cost of anything they demand, and their powers are almost dictatorial.”

On September 29, a dozen quality engineers from the Marshall Space Flight Center visited Kurdock for an “operational readiness inspection,” or ORI. The delegation was headed by Charlie Brooks, the robust and voluble chief of NASA's Optical Science Division. They spent most of the morning in a smoky, windowless conference room, grilling Kurdock and Rigby and a half-dozen others on the safety of the mirror-handling equipment.

“What about this space frame?” Brooks asked. “Has it been stress-tested?”

Kurdock told him that the space frame had supported a test weight twice as heavy as the mirror, without breaking.

“Was that after you welded in the extra struts, or before?” someone asked.

“Before. But of course the struts have made it even stronger.”

“Not necessarily,” said someone else. “Suppose you've got a crack in one of the strut welds. It lets loose, there's a sudden strain on the rest of the welds, and they all go in a chain reaction.”

“But there aren't any cracks,” said Kurdock.

“How do you know? Did you X-ray?”

“All right,” said Kurdock. “If it'll make you guys happy, we'll test the frame again with three times the rated load.”


“Action Item?” asked the secretary.

Brooks nodded, and pencils began scratching in the margins of 5088.

“Now,” said Brooks, “let's take a look at the speed controllers on those wash wands.”

They argued about the wash wands, then moved on to the lift cables and a dozen other details, adding an Action Item for each. Through it all, Kurdock kept his cool, but Rigby, sitting in the back of the room smoking cigarettes, grew increasingly flushed. Finally they came to the limit switch—a device that was supposed to shut off the electric motor that drew the mirror into the chamber, in time to prevent the mirror from crashing into the chamber wall.

“I think you should open up that switch and inspect the wiring,” said one of the quality men. “Suppose your man's got it wired up backwards. I've seen things like that happen.”

“Naw,” said Kurdock. “John's a very careful guy. Besides, if you look at paragraph fifteen-point-six-point-two-A, you'll see we have a man up there on the ladder, watching. If the mirror doesn't stop, there'll be plenty of time to shut the motor down manually.”

“Suppose the guy falls off the ladder,” said a quality man.

Rigby blew up. “That's foo-foo, and you know it!” he said, smoke boiling from his nostrils. “You're talking about a goddamned double failure. It's not gonna happen! Keep this up and we'll never get the thing coated.”

There was an awkward silence.

“It's okay, Bud,” said Kurdock. Then he added cheerily, “Might as well give the customer what he wants!”

Brooks smiled, Rigby scowled, and the pencils moved again.

The quality men spent the rest of that day, and all of the next, examining the equipment and watching a dress rehearsal with a dummy mirror. They were especially interested in the four technicians who had been trained to handle the mirror. The captain was Martin Geysalaer, a serious, soft-spoken, 42-year-old Dutch immigrant who had worked with Kurdock for ten years. The others were Bill O'Donnell, a shy 24-year-old with a profound Scottish brogue; Karl George, a strapping 37-year-old who wore designer jeans and a gold neck chain, and whose favorite expression was, “Hey, lighten up!”; and Rick Gagliardi, 26, who wore a black T-shirt and roared to work on a Harley-Davidson Electra-Glide. Each man's role in the coating had been carefully defined, and his movements choreographed to an extreme: how to hold a nut while twirling it onto a screw, which wrench to use for tightening each nut, where to lay the wrench afterwards. “We've practiced every step so many times, we can do it without thinking,” Gagliardi told me.

As a result, the rehearsal offered almost no surprises. “That's the way we want it,” said one of the quality men. “Nice and boring.”

When the two-day inspection was over, Kurdock and I sat in his office, a small, beige-walled compartment overrun with blueprints and potted plants.

Above his desk hung a company poster created for Space Telescope workers, showing a man with bright green eyes saying, “A GOOD IMAGE IS UP TO YOU!”

I asked Kurdock why NASA had been riding him so hard on the handling procedures.

“We've been known to break mirrors,” he said. “Not that we're careless, or anything. In this business, crap like that happens all the time. Look.” Turning to his bookshelf, he pulled down what appeared to be a case for a telephoto camera lens, opened it, and slid from its red-velvet interior a stunningly bright, golden cone that had a jagged wound where the point should have been. “I can't tell you what this is for,” he said. “That's classified. But you're looking at something most people think is impossible: a ninety-nine-percent-reflective gold coating.”

“What happened to it?” I asked.

“Guy dropped it.”


“Not very. Maybe ten thousand bucks. That's nothing. We've had accidents that ran close to a million. The worst one was probably Copernicus. You've heard about that?”

“Yeah, but not the details.”

“It was a thirty-six-inch mirror,” said Kurdock. “Weighed maybe three hundred pounds. Four guys were carrying it, and one of them trips over a two-by-four somebody left on the floor. Bang! No more mirror! The guy tried to jump under it to break its fall. Good thing he missed, or he'd've broken his leg. Actually, I don't think that one shattered. It just took a big divot out of the edge. But it was ruined. Took us nine months to make a new one. Boy, was NASA pissed.”

“Anybody lose his job?”

“Nah. Like I told you, stuff like that happens all the time. When you work with glass, you learn to expect it. No matter how much you plan, there's always a few stupid events you can't foresee. Things just happen.”

The results of the ORI were disappointing. Kurdock ended up with eighteen different Action Items—enough to push Coating Day back another two weeks, to November 15. It was the third time the date had slipped since he received the big glass.

As Kurdock's supervisor for Hubble Telescope matters, Bud Rigby had to phone the bad news to Fritjof Speer, NASA's project manager in Huntsville. Speer was in a rotten mood when the call came. He had just learned that Ronald Reagan was about to lop twelve percent off NASA's budget next year if the agency couldn't better explain its performance in 1981. The press was reporting that “problems at Perkin-Elmer” had forced NASA to move back the Space Telescope's launch by another eighteen months. NASA desperately needed something—anything—to show for all the money it had spent this year, and the most imminent feat was the completion of the Hubble Telescope mirror. So, when Speer heard the schedule had slipped again, he shouted in his imperious German accent, “Vell, I hope at least that iss a firm date!”

“Oh, I wouldn't say that,” Rigby replied cheerily.

Speer could barely control his anger at this blithe remark. The next morning, hearing that one of Rigby's supervisors was visiting Huntsville, he summoned the supervisor to his office. “Do you know what that man said to me?” he cried. It took the supervisor half an hour to calm Speer down.

“That's Bud for you,” Kurdock remarked when told of this incident. “He specializes in hysteria. Every time someone lights a match, he pours gasoline on it.”

It was no secret that Jack Kurdock and Bud Rigby didn't always get along. Rigby was officially in charge of the mirror from start to finish, and that gave him power over Kurdock. But Kurdock was head of the coating facility, and that gave him power over Rigby. Kurdock didn't mind saying so, either. “Once the mirror came through that door, it was mine,” he once told Rigby. “I don't care what happened to it beforehand, and I don't care what happens to it afterwards. Right now it's my responsibility, and nobody goes near it without my say-so.”

Rigby apparently assented to this. In early October, he meekly asked Kurdock whether he could attend the coating. “I won't do anything,” he promised. “Just get me a chair and I'll sit quietly and watch. Now, you don't have to answer right away—maybe you'd like to think about it.”

“I've already thought about it,” said Kurdock, “and the answer is no.”

At the time, Kurdock was still insisting that no one but he and his technicians attend the coating. “I don't need distractions,” he told me darkly. “There's too much that can go wrong.”

Kurdock's team spent most of October working on the Action Items. The worst item was completing the test runs. The team still hadn't achieved more than four flawless runs in a row. Time and again, they watched the voltage needles climb into the danger zone and heard the sickening rattle of the coolant boiling in the guns. The problem, as usual, was the power supplies. “The vendors finally admitted they only manufactured six of this model—and I own four of them,” Kurdock told me bitterly. “If I'd known that, I wouldn't have bought the damned things.”

Because each test run required a whole day of preparation and cleanup, the team soon found itself working double shifts. Kurdock was exhausted. Besides wrestling with the Hubble Telescope, he was trying desperately to get a new wing built for coating Micralign mirrors.

Around mid October, the mood at Perkin-Elmer blackened. The company had been forced to lay off fifty workers in its optical division, many of them high-level engineers. More than 100 others had taken early retirement or jumped ship in the few months preceding the layoff. “The handwriting's on the wall,” said one employee. “All of our projects seem to be ending, none starting. If only we could get SOT...”

It was November 5 before Kurdock's team reached Test Run Number 6. They were too tired to celebrate, even though the results were encouraging. The test mirrors averaged 73-percent reflectivity—three points better than spec.

On Thursday, November 6, Kurdock finally got permission to open the mirror crate. After looking at the big glass, he suddenly told his team he wasn't feeling well, and went home. His wife called the next morning to say he had the flu and was down with a temperature of 105 degrees.

“He picked a good time for it,” said Kent Meserve, Perkin-Elmer's project manager for the Hubble Telescope. Meserve ordered the remaining work to go ahead anyway. With a little luck, he thought, the coating might be finished by November 19—the day his company would defend its bid for SOT.

At the coating-room door a few mornings later, I met team member Rick Gagliardi, who had agreed to let me have my first look at the mirror. He handed me a jumpsuit, a surgeon's mask, a hood, and a pair of white booties with tacky soles, meant to prevent me from kicking up any dust. “We're going into a Class Ten Thousand environment,” he said. The previous weekend, a cleaning crew had scrubbed and polished every square inch of the room, including its 24-foot ceiling. An electronic monitor had been set up to make sure the air contained no more than 10,000 dust particles per cubic meter—1,000 times fewer than in a hospital operating room.

As I was writing this down, a man from Quality Control stepped up and said to Gagliardi, “You're not going to let him in with that pencil, I hope.”

Gagliardi handed me a ball-point pen. “NASA doesn't like pencil dust,” he explained.

Gagliardi punched a secret code, and the coating-room door slid open. We stepped into a glass booth—the “air shower,” he called it—where he pressed another button. There was a deafening blast of air from the ceiling and a strong suction through the grating in the floor, meant to rid us of stray dust particles. It lasted about thirty seconds.

“Did you volunteer for this job?” I shouted.

“Nah. I got transferred in from Micralign during the 'Seventy-Four recession.”

“Like it?”

“It's a job. Gets pretty boring sometimes. They've run us through the procedures so many times we can do them in our sleep.”

We stepped out and walked past the coating chamber. Up ahead, in the middle of the floor, was the mirror, lying face-down on a ruffle of white lens tissue. It looked like a gigantic Crist-O-Mint Lifesaver. An optical inspector, kneeling at the far side, was scanning its slightly convex, polished back with an eye loupe, comparing it with a map of all the blemishes that had been recorded before it left Rigby's shop.

Moving closer, I saw the “egg-crate” pattern of glass slats that divided the mirror's hollow interior. Some of the compartments near the edge appeared to be caked inside with a whitish residue. “Probably glass dust,” said the man from Quality, “and polishing compound.” The foreign matter had apparently entered through a row of quarter-inch holes all around the mirror's flank. These, said the quality man, were to equalize the air pressure inside the mirror and out. Without them, its face would bow in or out a few millionths of an inch with every change in the barometer.

“Okay if I feel the mirror?” I asked. Today was one of the last days anyone would be allowed to touch even the back with his bare hand.

The quality man nodded, and I began bending over.

“Wait!” he said. “Your glasses!”

Gagliardi brought over a length of wire, and the quality man tied the stems of my spectacles behind my head.

The mirror felt strangely cold, as though it had been cast in metal. I removed my hand and watched the moist print evaporate into a frosty archipelago of fingertips, then vanish.

“I've found something,” said the optical inspector. He had quit moving the loupe and was motioning to the quality man. Everybody crowded around.

Under the loupe was a short, curving crack, blunt at one end and sharp at the other. “It's not on the map,” the inspector said gravely.

“Wait a minute,” said one of the technicians. He knelt beside the mirror, lifted the loupe, and blew his breath on the crack. It suddenly skittered across the surface, drawing whoops of laughter from the onlookers. The “crack” was an eyelash.

Hours later, the mirror was examined by Kurdock's deputy, Ed Strouse. He was alarmed at the whitish deposits inside the edge compartments. “That stuff's probably got oils and emulsifiers and everything else in it,” he told the quality man. “I mean, we're talking serious hydrocarbons here. If they come out during the coating, they're gonna kill us in the UV.”

Strouse was afraid some of the ingredients might evaporate, or “outgas,” under the high vacuum in the chamber, then condense on the glass and ruin the coating. After talking with a feverish Kurdock by phone, he told the quality man that he wanted the mirror put into the chamber and outgassed before being washed, instead of afterwards, as originally planned.

The quality man shook his head. “You'd be adding a whole lift cycle,” he said. “It's too risky.”

“It's too risky not to,” countered Strouse. “You want us to wreck the schedule? If we don't get that stuff out of there now, we may end up having to strip a bad coating and do it all over again. The turnaround time could be months.”

“The schedule isn't worth that much,” said the quality man. “If we go changing the sequence at this late date and something stupid happens, then where'll we be? I won't allow it. I don't think Rigby will, either.”

They are not gonna outgas that mirror!” Rigby cried when I mentioned Strouse and Kurdock's idea. “They're gonna follow the goddamned plan we set up, and if they're gonna revise it, I'm gonna know about it beforehand!”

He stopped to catch his breath, then offered more calmly: “Any changes that are made will be made by committee.”

While the committee conferred, Kurdock's crew went ahead with preparations to mate the space frame to the mirror. On Saturday morning, November 14, I went along to watch the first lifts.

“Who let you in?” barked a man I had never seen before. He was hawk-nosed, with black hair slicked back in DA style, and had searching, coal-black eyes.

I explained that I had cleared my visit with Corporate.

“You're not on the Authorized Personnel List,” said the man. “I don't know you. How do I know you aren't some nut with a gun? You got a cold? You got a cold, you don't get into the clean room.”

“Lighten up, Mike,” said Karl George. “He's been here before. They must've fouled up the paperwork.”

“Well, see that it doesn't happen again. I'm not gonna be responsible for any more slips.”

I asked the man who he was.

“Mike Vagnone. Defense Contract Administration Service.”

“But this is a civilian contract,” I said.

“It's something critical,” said Vagnone. “They got something critical, they call us.”

Later, I learned there was a special reason for cautiousness. A few months earlier, just before the mirror was delivered to Kurdock, he had come to work early one morning and discovered the glass shattered in the plant's front door. He also found a hole in an Equal Opportunity Employment poster hanging behind the reception desk. The police dug a .38-caliber bullet out of the hole. Kurdock theorized that the culprit was one of two employees who had recently been laid off. He decided not to take any chances. Everyone knew about the drunken technician who had emptied a Smith-and-Wesson automatic into a 103-inch NASA mirror in Texas a few years back, and everyone knew about the bullet craters found in the Palomar mirror's armor after its cross-country train trip in 1946. Something about large mirrors drew out the worst in people.

Another source of worry was a last-minute change in a piece of lifting equipment—the Hydra-Set. This was a weight scale to be interposed between the lift cable and the space frame, so that the crane operator, by watching its dial, could lower the 1,281-pound space frame over the mirror with exacting gentleness. A few days earlier, Strouse had gotten word that the bottom ring on a Hydra-Set of the same model had broken during a lift at a General Electric plant in the Midwest. He hurriedly substituted another model—this one hydraulic where the other had been mechanical. Having worked with the mechanical Hydra-Set for nearly a year, Geysalaer, the crane operator, felt uneasy with the hydraulic. One annoying feature was that its valve handles had to be locked together with a separate, aluminum bracket when it was not in use. Without pockets in his jumpsuit, Geysalaer found it easy to forget where he had left the bracket after each lift. No one had specified where to put it in 5088.

The technicians told me they didn't mind coming in on Saturday. “We get overtime,” said Karl George. “I'd just as soon have the extra sleep, though. I'd hate to tell you how late I was up last night. Wife and I went out dancing, you know.”

While Geysalaer prepared the Hydra-Set, Vagnone conferred with Tom Dubos, a quality man from Perkin-Elmer. Gagliardi, George, and the fourth technician, Bill O'Donnell, fastened the cables to the space frame, which sat fifteen feet from the mirror. When Dubos and Vagnone were satisfied that the cables had been properly attached, they stamped their copies of 5088 and told Geysalaer to go ahead. The space frame was to be lifted eight feet into the air and swung over the mirror, then lowered onto it for fastening. Geysalaer pushed a button in the control paddle hanging from the ceiling. With nine pairs of eyes watching, the cables tightened, the Hydra-Set needle climbed to 1,281, and the Space Frame slowly began rising. Dubos and Vagnone began circling, heads up and eyes darting.

Just as the load reached a height of seven feet, Vagnone shouted, “Hold it!”

There was a loud clunk as Geysalaer hit the STOP button. The space frame hung above us, wobbling like a giant chandelier.

“There's something on top of that Hydra-Set,” explained Vagnone.

Something black and irregular was peeking over the edge.

Gingerly, Geysalaer let the space frame down, stopping it a foot from the floor. Dubos and Vagnone brought a stepladder over, and Vagnone climbed up and picked off the object. It was the metal bracket for locking the valve handles.

“I had a friggin' feeling, I don't know why,” Vagnone declared proudly, smiling and wiping the back of his head. He tossed the bracket onto the tool table, where it gave a resounding clang, and walked away, shaking his head. The technicians were silent.

“That's three things already this morning,” Dubos said to Vagnone. “Got a half-inch nut, got a washer, and now this. Not bad for one day, huh?”

After work, I found Geysalaer sitting on the bench outside the coating-room door, staring blankly into his locker. I asked him what would have happened if the bracket had fallen on the mirror.

“It might've hit the edge of the center hole and made a nick in the glass,” he said. “It would've taken months just to decide what to do about it.”

The Bracket Incident was a low point for Kurdock. “Maybe I shouldn't have been putting all that time into the new Micralign wing,” he told me guiltily. “Maybe I wouldn't have gotten sick. Maybe I would've been there and seen the bracket before the lift.”

In Washington later that week, Perkin-Elmer was defending its bid for the SOT contract. “What makes you think you can do a good job on SOT, when you've had all this trouble with the Hubble Telescope?” a NASA executive asked.

The Perkin-Elmer man thought for a minute. “We've never built a Hubble Telescope before,” he said calmly. “Have you?”

A few days later, I asked Horace McDonell whether his company could survive without its NASA contracts.

“There was a Perkin-Elmer before there was a NASA,” he replied coldly. “And I expect there will be a Perkin-Elmer when NASA is gone.”

He's just a little sensitive because he's been put on notice that he hasn't kept ahead of his technical problems as well as he should,” NASA chief James Beggs said of McDonell on November 23. Lately, Beggs had been phoning McDonell daily to check on Kurdock's progress. McDonell, in turn, had taken to dropping in on Kurdock. (“He's awfully nice,” Kurdock told me, “but I wish he'd—well, frankly, he gives me the heebie-jeebies. I mean, the guy's head of a billion-dollar corporation. I like to have my work noticed now and then, but I don't need that kind of attention.”)

Kurdock, finally over the flu, had come back to work full of energy and resolve. “From now on, I'm spending all my time on the telescope mirror,” he told me.

“He'd better be,” said Kent Meserve. By missing the mid-November deadline, Kurdock had not only harmed his company's chances of winning SOT, but also was threatening NASA's launch schedule. “The mirror is definitely on what we call the critical path,” Fritjof Speer told me on November 22. “If it isn't coated very soon, that will unfortunately be on my ticket.”

Speer was urging Meserve to have the mirror finished by 9 a.m. Tuesday, December 8, when Perkin-Elmer was scheduled for its next Quarterly Review by NASA. “They really put us on the rack at the last one,” Meserve told me. “I hate to think of what would happen this time.” At stake was a quarterly performance premium ranging from zero to several millions of dollars.

By Thanksgiving, Kurdock began to think he might actually meet the new deadline, now thirteen days away. The mirror had been thoroughly outgassed (Rigby had been overruled by the committee), and needed only to be washed.

A serious hitch developed, however. During a pre-wash inspection, the team discovered dozens of tiny pits where bubbles had broken through the surface during polishing. Every one of the pits was clogged with polishing compound. “We've got to get that gunk out of there before we can wash,” Kurdock told me. “God knows how we'll do it; some of the pits are almost microscopic.”

Equipped with sharpened toothpicks and dental tools, the team set to work. The job took them all day, all night, and part of the next morning.

The wash took even longer, but it was largely automatic. First, the team bolted the mirror and space frame into what appeared to be a giant shaving-mirror stand. After cranking the mirror upright, they wheeled the assembly into a large shower stall in one corner of the room. There, a pair of rotating wash wands sprayed the surface all day with a soap solution. Then the rinse cycle began, using ultra-pure, thrice-distilled water.

No one knew exactly how long the rinse would last. The team simply shut off the water every few hours in order to see how the mirror was draining. On the third day, Kurdock was delighted to see a perfect, single sheet thinning itself on the surface. Under the floodlights, the sheet exhibited interference effects like those seen in a soap bubble. Waves of crimson, yellow, green, and violet cascaded over the mirror, until the film of water became so thin that the mirror suddenly turned black.

Kurdock could have coated the mirror on Saturday, December 4. The glass had been installed in the chamber, the pressures looked good, and the equipment was behaving beautifully. But the coating team was exhausted. “They're looking kind of punchy,” Kurdock told Meserve. “I don't think it's wise to have them around the equipment.” He decided to let the team rest all weekend and coat on Monday.

By evening, however, he found himself more nervous about the equipment than about the men. “As long as everything's running right, let's not press our luck,” he told them. “We'll coat tomorrow.”

There was one other reason he preferred doing the job on a Sunday: It would cut down on the number of spectators.

When Kurdock arose the next morning, he saw that Coating Day was going to be cold and gray and windy. He suddenly realized that he'd been preparing for this day for five years—ever since the morning when Dan McCarthy, head of Perkin-Elmer's OTA proposal team, had phoned to say, “We'll need an estimate on coating a ninety-four-inch telescope mirror.” Kurdock had protested that he didn't want such a job, but he went ahead and did the estimate anyway, feeling certain that Perkin-Elmer wouldn't win the contract. How naive he had been!

He thought about the morning last July—it seemed years ago—when the tractor-trailer had finally pulled into the parking lot bearing Rigby's masterpiece. What a circus! The glass had been polished at a Perkin-Elmer plant seventeen miles to the north, and the quality men had tied themselves in knots worrying about security along the route. One of them had noticed a roadside cemetery with gravestones big enough for gunmen to hide behind. He tested the mirror crate with a Smith-and-Wesson automatic, and found it wanting. “I think we need armor plating,” he announced at a high-level meeting.

Rigby snorted at this. “What are you trying to do—add another year to the schedule?” he said. “Just put the goddamned thing on the truck and get it out of here.”

Finally, they settled on a compromise. An eyes-only memo went out: On Sunday morning, July 14, there would be a practice run with an empty mirror crate. It would be a full-dress rehearsal aimed at testing every detail of the transfer—police escorts, road closings, radio communications, even lifting the crate off the truck when it arrived at the coating facility.

The rehearsal went smoothly. The only surprise came as Geysalaer was preparing for the final lift. While the technicians attached the cables to the crate, Kurdock leaned over and whispered to Geysalaer: “The mirror's in there, Martin. No horsing around!” And indeed the mirror was there. No one below Kurdock had known the truth.

When Kurdock reached his office on the morning of the coating, he found the place crawling with more than twenty onlookers. NASA had put half-a-dozen quality men on a plane from Huntsville. They were all there, with their aluminum attachés and their Alabama accents. Rigby was there, too, thanks to a hint from President McDonell that it wouldn't be fair to keep him away—or anyone else important to the venture, such as certain vice presidents.

McDonell himself was playing tennis that morning. “I might be able to make it if you can hold off until one o'clock,” he had told Kurdock.

The air was festive at first. After watching a few tests and preliminary procedures, the group moved to the conference room where the Operational Readiness Inspection had been held. Somebody ordered pizzas. Soon, the room was full of greasy napkins and twenty men with their noses in soft-drink cans.

“I bet Speer'd get a comfortable feeling if he saw this was the team to coat the Space Telescope primary,” Rigby cracked.

“Hell, we were the low bidders!” responded a Perkin-Elmer quality man. “What more do you want?”

“Hey, let's take a picture and tell Speer we're about to go into the clean room,” someone suggested.

“You guys wanta move this pizza over to the coating room?” Kurdock asked. “I'm sure NASA wouldn't mind.”

The others laughed.

“How come I'm the only one who's nervous?” one of the visitors asked.

The others looked at him.

“What makes you think we aren't nervous?” said Rigby.

Kurdock grew quiet at this point, and moved away from the table. He sat on the floor in a corner, eating a slice of pizza. After a while, he put the pizza down and sat silently with his legs straight in front of him, staring at his brown penny loafers.

At quarter to one, Kurdock got up and summoned Gagliardi, Geysalaer, George, and O'Donnell for a last-minute talk in his office.

“I just want you guys to know,” he said after closing the door, “that whatever happens, I'm with you.” The team sat shuffling their feet and staring at the floor. “Now, I know we have a lot of people watching, but we can't let that rattle us. Just keep your cool. Nobody's holding a gun to your head. If something doesn't look quite right, we don't have to coat today—no matter what anybody says about the Quarterly Review and all that crap. All right? Listen, you guys are the best vacuum coating team in the world, and I'm proud to be working with you. Let's go out there and show 'em how to coat a mirror.”

Before entering the clean room, all of the visitors were required to put on jumpsuits, cowls, and booties. They looked like a convention of surgeons. Some of those from Perkin-Elmer balked at the booties, but Kurdock told them, “We gotta go by the book on this one. You never know who might show up.”

As we stepped out of the air shower, a deep chugging sound filled our ears—the “roughing” pumps on the chamber. “Pressure looks good,” said Kurdock, stepping to the control panel. Red numerals indicated 2.4 x 10-8 Torr, which meant that the space inside the chamber, about as voluminous as an average living room, contained less than a thousandth of a thimbleful of air. Before the coating could begin, however, nearly all of that would have to be drawn out by even more powerful pumps.

As the technicians began taking their places, Kurdock seemed to be getting jumpy. The crowd had pressed to within a couple of feet of the computer console from which Karl George was supposed to key in the commands. Some of the visitors had their backs against the adjoining control panel, leaving no room for Martin Geysalaer to navigate. “Everybody back behind the table!” Kurdock barked. He and Mike Vagnone pushed a white formica-topped table away from the console, clearing a space about ten feet square. Vagnone plopped his copy of 5088 on the table and took out his rubber stamp and red ink pad. Kurdock sat on a stool beside the table. “Now, let's not get in a hurry,” he said to George. “Remember what I said.” George sat at the console while Gagliardi and O'Donnell moved to the chamber's viewing ports. All four technicians donned headphones, in order to hear each other above the pump noise.

The first task was to drive the pressure ten times lower than it already was. Over a period of fifteen minutes, the team switched on a turbo-pump, then a pair of cryo-pumps, and finally a titanium pump that drew out most of the remaining oxygen by means of a chemical reaction. Through it all, Kurdock sat staring at the control panel and rubbing his chin. As time passed, his face seemed to drain.

“Nervous?” asked John Humphreys, head of the Huntsville delegation.

“Bet your ass,” said Kurdock. “There's a hell of a lot can go wrong.”

“Hey, McDonell's out there!” said one of the spectators, turning from the glass door behind us.

“Oh, God,” muttered Kurdock, “that's all I need.” He got down off his stool, studied the stool, and said to Vagnone, “Get rid of that.” Then he went out to help President McDonell suit up.

McDonell was a tall, grandfatherly man with a pointed nose and a perpetual smile. As Kurdock rummaged through the lockers for a pair of booties, McDonell asked if he was nervous.

“A little,” said Kurdock.

“Well, I guess you'd be crazy if you weren't!” McDonell said expansively.

There weren't any booties. So, a minute later, the crowd saw McDonell stepping out of the air shower wearing naked black oxfords. “Hi, Bud!” he said when he caught sight of Rigby. He patted Rigby on the back and stood next to him while Kurdock—now standing—gave Vagnone a nod indicating that he was ready to begin.

“Initiate rotation!” called Vagnone, reading from 5088.

George punched a few keys on the computer. There was a loud clunk, and from inside the chamber came the sound of dozens of steel balls clacking together as the ring gear, with the mirror nested inside it, began turning on its race. It sounded as if we were standing out-side a busy billiard parlor.

“Rotation established,” said Geysalaer. The control panel indicated 3 r.p.m.

“Rotation established,” repeated Vagnone. He marked the step in 5088 with his stamp, which made a little picture of an eagle with three stars under it.

Now it was time for the coating itself. First, four of the electron guns would be powered up. If their voltages looked good, four metal shutters would then be opened to let the electron beams strike and begin vaporizing the aluminum. As the aluminum built up on the mirror, Karl George would see a vertical line growing on his computer screen, indicating the film's thickness. The line would inch toward a horizontal bar marking the target thickness. The moment it touched, George would close the shutters and the aluminum layer would be complete. Then would come the critical stage: In less than two minutes, the team would have to power up the other four guns and open the shutters on the magnesium fluoride. If they took any longer, the aluminum would begin oxidizing before it was sealed, and the mirror's ultraviolet reflectivity would suffer.

“You guys ready?” asked Kurdock.

The others nodded.

“All right. Aluminum guns!”

The guns made a roaring sound in the chamber, as if a couple of lions were scrapping inside. Kurdock's eyes were on the control panel, watching the indicator needles on the power supplies. All four needles had jumped to 9,000 volts and were holding steady. A flicker of relief passed over his face. “Open the shutters!” he said.

The roar suddenly deepened, and a white line sprouted on George's computer screen.

Kurdock looked over at McDonell and said, “Wanna take a look?”

Geysalaer ushered the president to one of the tiny glass viewing ports in the side of the chamber.

While McDonell knelt and peeked through the glass, I did the same at a neighboring port. The inside of the chamber was bathed in a golden light, like that of a late summer after-noon. In the nearest crucible, a lump of aluminum glowed pink where the electron beam was boring into it. The vaporizing aluminum did not make a visible cloud, but as I watched the mirror rotating overhead, I could see a grayness blooming on its surface, as if someone were standing far off with a can of spray paint. Gradually, the gray clarified and took on a marvelous brilliance. I saw features of the upper chamber wall reflected in the mirror's edge zones, magnified as if in a cosmetic mirror. Then it was someone else's turn to look.

Back at the console, George was holding a finger above the STOP key as the thickness line approached the setpoint. He jabbed the key at exactly the right moment. The roar changed pitch again as the shutters closed.

Kurdock clapped his hands and said, “Okay, let's seal 'er up!” His crew had only two minutes to begin depositing the magnesium fluoride.

Everything seemed to happen faster now. George's fingers flew over the keyboard. Geysalaer leaped for the right switches on the control panel. Gagliardi talked excitedly on the intercom to O'Donnell, who had his nose pressed to the nearest port.

Meanwhile, Kurdock's eyes were glued to the voltmeters. Panic invaded his face.

The needle on the power supply for Gun Number One was still on zero. All the others had long since leveled off at 9,000. Something was wrong with Gun One. The clock was ticking: twenty seconds, twenty-five....

“What's going on, Bill?” Kurdock said into his intercom mike. “Can you see anything in there?”

O'Donnell, at the viewing port, shook his head. Thirty seconds had passed. Inside the chamber, oxygen atoms would already be attacking the aluminum.

George looked at Kurdock, his eyes pleading for permission to open the shutters. It was possible to meet spec with three guns—but not if the team waited the whole two minutes.

“Come on, Gun One!” said Kurdock, glowering at the voltmeter. “Come on!”

Still the needle wouldn't budge.

“Go without it!” said George. “There isn't time!”

Kurdock held up a hand, as if to shush him. The clock passed eighty seconds. O'Donnell and Gagliardi were jabbering on the intercom. Geysalaer had turned his back on the instrument panel and was staring beseechingly at Kurdock.

“Go!” Kurdock blurted. His face bore a look of pain and disgust.

Then a miracle happened. The instant the shutters opened, Gun One seemed to awaken. Its needle hopped to 9,000 and began flickering in perfect unison with the others.

Kurdock let out a whoop that set the spectators laughing.

“Aw right!” said George.

At 53 minutes and 11 seconds after one o'clock, the heart of the Hubble Telescope was at last complete. Rigby, hearing the shutters close, shouted “Hey!” and jammed a fist into the air. While the rest of the crowd applauded, he warmly shook Kurdock's hand. “Good show!” he said.

“Hey, what'd you expect?” replied Kurdock. He motioned toward the technicians. “Best vacuum team in the world!”

Soon, the room was full of the sound of popping champagne corks. The men sipped Korbel Brut 1976 out of plastic coffee cups.

In one corner, Rigby, McDonell, Kurdock, and Meserve were reminiscing.

“Remember all those folks telling us we'd never make this mirror?” said McDonell.

Meserve nodded knowingly. “We'd have to get Kodak to make a backup. We'd have to let Kodak make both of them....”

“Well, I know one thing,” said Rigby. “I'll never see another mirror like this one. Not in my lifetime.”

“Aw, Bud, don't say that,” said Meserve.

“It's true,” said Rigby. He tossed down his last swallow of champagne and moved away, suddenly looking old and weary.

Meserve changed the subject. “Any bets on the reflectivity?”

“Don't worry,” said Kurdock. “It'll pass.”

The reflectivity test was scheduled for the following afternoon. In the morning, Kurdock's team vented the chamber and opened its door. They knelt in the doorway and aimed a floodlight at the ceiling.

For an instant Kurdock thought someone had stolen the mirror—nothing was visible up there, only an inexplicably high ceiling. Then he realized that he was looking at a reflection of the chamber floor in an extraordinarily bright mirror. “God, that's pretty!” he cried. There was a chorus of wows and amens. “It's almost as bright as a silver mirror,” said Kurdock.

He switched off the light. “'Course, that doesn't mean anything. For all we know, it's dead black in the UV.”

“'Buck says it's seventy-six percent,” said Gagliardi. Spec was only 70 percent.

“I hope not,” said Kurdock. “If it's that high, they'll try to make us recoat the secondary.” The telescope's 13-inch secondary mirror, coated two weeks earlier in a much smaller chamber, had come in at 73-percent reflectivity.

For the test, the team removed from the chamber three “witness pieces”—sample mirrors which had been coated along with the main one. Each was about the size and shape of a checker.

In a laboratory near the coating room, Gagliardi installed the first witness piece in a vacuum spectrophotometer—a small chamber in which a light beam of gradually changing hue bounces off the sample while photocells measure the percentage of light it reflects. Gagliardi had hooked the machine to a chart recorder, so that he and the others could see the results immediately.

They watched silently as the recorder pen traced a squiggle of green ink across the page, showing the reflectivity at the red end of the spectrum first, then advancing toward the UV. As the pen neared the target wave-length, the line began dipping and diving, drawing a couple of “whoa!”s and a “yikes!” from the technicians. Gagliardi joked that they might as well pick up their pink slips—the line was already below eighty percent and headed steeply down. But it turned up-ward in the last minute and hit the target at an incredible 81 percent—only three points below theoretical perfection.

“That can't be,” said George. “There's something wrong with the machine.”

Gagliardi shook his head. “I just calibrated it.”

Kurdock came in and looked at the chart. “I can't believe that,” he said. “You guys keep a lid on that, hear? I don't want Humphreys to think we have a perfect mirror till we're sure.” It would be Kurdock's job to report the results to the head of the Huntsville delegation.

Within the hour, though, samples two and three confirmed the UV reflectivity at eighty percent. The technicians whooped and hollered. “Best in the world!” said Gagliardi, tapping his chest with his thumb.

Kurdock had mixed feelings. “Engineers don't like surprises,” he told me. “Not even good surprises.”

In his meeting with John Humphreys after the test, Kurdock insisted on reporting the reflectivity at only 78 percent. “It'll give us a little room down the road,” he said, “in case we get some mysterious tarnishing, or some-thing.” Humphreys finally consented, writing 78 in the book.

Toward the end of the day, Kurdock and Humphreys went into Kurdock's office to phone the test results to Charlie Jones, chief of NASA's optical branch in Huntsville. It was, in a sense, the final act in the coating. While the secretary placed the call, the men stood with their hands in their pockets, looking at the speakerphone on Kurdock's desk.

“You watch,” Kurdock said to Humphreys. “Charlie'll say, 'Seventy-eight? How much cheaper could you have gotten seventy-one?”

The phone rang.

“Charlie,” said Humphreys. “Ready for the good news?”

“Shore!” said a deep, drawling voice.

“Now, I know this figure will be unbelievable,” said Humphreys, “but I was there and saw it with my own eyes. Here, I'll let Jack tell you.”

Kurdock spoke up. “Charlie, we got seventy-eight percent in the UV.”

A loud, lingering whistle erupted from the speakerphone. “Man, that's in there!” said Jones.

There was a long pause. Kurdock held up a finger as if to say, “Watch!”

“You know,” Jones said thoughtfully, “I'm wondering if you couldn't have saved a little money in there somewhere, maybe by—”

Kurdock dropped the finger and gave Humphreys a triumphant smile.

That evening, I sat with Kurdock in his office, reviewing the day's events. “Jones seemed pretty happy,” I said.

“Pretty happy? You don't know Charlie. The man was ecstatic,” said Kurdock. “Look—look at what we did for him.” He seized a pencil and a piece of paper and began calculating. “To get the amount of light coming through the telescope, you multiply the reflectivity of the primary mirror times the reflectivity of the secondary, right? Okay, the specs were seventy percent times sixty-seven percent, which equals forty-seven percent. So, they expected forty-seven percent of the light entering the telescope to get through to the cameras. Okay? Now, look at what they actually got: seventy-eight percent on the primary times seventy-three on the secondary—that's fifty-five percent. They asked for forty-seven, we delivered fifty-five. In other words, they got sixteen percent more light coming through the telescope than they paid for. Hell, that's probably a billion light-years added to the telescope's reach—and it didn't cost 'em a cent.”

He tossed the pencil down and leaned back in his swivel chair with his hands folded behind his head. “Yeah, you'd better believe they're happy,” he said. “They're deliriously happy.”

Apparently, Kurdock was right. NASA gave Meserve a standing ovation at the Quarterly Review the next morning. And six months later, Perkin-Elmer got the SOT contract.

III. A Grim Opportunity

Until the Space Shuttle Challenger's accident in January 1986, the Hubble Telescope was scheduled for launch in October of that year—already 18 months later than originally planned. It had missed Halley's Comet and the Uranus flyby. But its tardiness was a blessing in disguise. If Rigby hadn't opted for the smoothing run in the spring of 1981, or stuck to his guns when his superiors tried to take the glass away from him; or if Kurdock had bought more reliable power supplies, or put less of his energy into coating Micralign mirrors, the Big Glass might well have ended up on the bottom of the Atlantic Ocean.

During the long wait for the Shuttle's redesign, the Hubble rested in a huge “clean room” at a Lockheed Spacecraft and Missiles plant in Sunnyvale, California—1,000 times cleaner than Perkin-Elmer's coating room. The telescope wasn't in mothballs, however. Lock-heed and the 240 personnel at the Space Telescope Science Institute in Baltimore, from which the telescope would be controlled, seized the opportunity to make improvements. The most important was in the software that controls the scheduling of observations. “It used to take thirty times as long to prepare for an observation as to actually do it,” said Riccardo Giacconi, the Institute's director. “Now the planning will be shorter than the execution.”

The launch delay also gave engineers time to improve some of the cameras aboard the telescope, which weren't as sensitive as hoped. “Fortunately, the mirror's performance has already offset most that problem,” said Giacconi.

Giacconi never dreamed how wrong that statement would turn out to be.

IV. The Big Fix

When the Hubble Telescope was finally launched, in 1990, the news media gave it the kind of attention once reserved for the planetary flybys of Voyagers I and II. There wasn't much to see at first, however—just blurry videos of the famous Canada arm setting the telescope adrift 370 miles above the earth. Weeks of testing and fine-tuning would be required before the instrument could deliver its first images, said NASA. And so the world waited.

The bad news leaked out only a few days later. Technicians at the Space Telescope Science Institute were having trouble getting the Hubble focused. They had tried issuing commands that moved the primary and secondary mirrors closer together and farther apart, much as a football spectator might adjust his binoculars. They had even tried tweaking an array of tiny actuators pressing on the big mirror's back, to change its shape by a few millionths of an inch. Still there was no improvement. Distant stars looked like the “big, fuzzy cotton balls” Rigby had once described as the mark of a misshapen mirror.

By the time I phoned Rigby, computer studies of the images had revealed the startling truth. Each cotton ball, although fuzzy, was perfectly round, and it faded with exquisite evenness from its center outward. This proved that the Big Glass had not been warped by the absence of gravity—it was just as smooth and regular as the day it had left Perkin-Elmer. “It's still the most perfect mirror ever made,” Rigby told me. “The only problem is, it's perfectly wrong.”

Somewhere along the line, Rigby's team had made the same mistake as an optician who fashions a perfectly shaped eyeglass lens, but to the wrong prescription. The face of the Big Glass was a flawless hyperboloid, as planned. The only trouble was, its curvature was too shallow by 80 millionths of an inch.

By Rigby's standards, this was a colossal error. “They checked our math,” he told me, referring to the NASA panel investigating the problem. “They checked every equation, every measurement. They found zero mistakes. Zero. That means it could be only one thing: a problem in our test equipment.”

Somehow, Montagnino's interferometer hadn't been telling the truth. Over the next few weeks, the investigators pored over its design and construction, looking for flaws.

They finally zeroed in on the collimator assembly—a pair of lenses mounted inside a metal barrel near the top of the interferometer. The collimator was designed to transmit the laser beams that bounced off the mirror during the measuring process. To make the beams perfectly parallel, the two collimator lenses were spaced an exact distance apart—or so Rigby had thought.

The spacer for the lenses was a metal bar of precise length. Like everything else in the instrument's light path, it had been sprayed with a dead-black paint, in order to prevent extraneous reflections. The paint's thickness had been carefully figured into the bar's length. Now, viewing one end of the bar under a microscope, the investigators discovered that a tiny fleck of the paint was missing. The bar was too short—by just enough to explain the Hubble's problem.

Neither Rigby nor Perkin-Elmer paid a heavy price for the oversight. Rigby admitted having seen evidence that the interferometer was acting strangely.

But the clues had come from an auxiliary testing method “that just didn't have the pedigree we'd established with ours,” he said. The investigators ruled that Perkin-Elmer had acted in good faith.

It was clear, too, that the mistake might be fixable. Like an eye patient wearing the wrong prescription, the Hubble could, in theory, be fitted with corrective lenses that would exactly cancel the error. And the correctors would not have to be especially large. If placed far down the light path, just before it entered the tiny opening in each camera, they could be the size of a dime. Spacewalking technicians could install them easily.

On December 6 and 7, 1993, that's exactly what four NASA astronauts did. Two of them replaced the entire Wide Field Planetary Camera with a new model. Its corrector was a tiny lens inside the unit. The other two installed a cluster of tiny mirrors designed to correct the remaining cameras.

The results of this repair came into the Space Telescope Science Institute a few days later. Whereas the telescope had earlier concentrated only 15 percent of a star's light into a point, the figure was now 85 percent—10 percent better than spec. After eighteen years and $2 billion, the Big Glass had finally become the instrument it was meant it to be.

In the years since the Big Fix, the telescope has dazzled astronomers and the public with its discoveries. It found a Jupiter-sized planet orbiting a nearby star in the Big Dipper. It detected a black hole almost as large as our solar system, containing the mass of three billion suns. It took pictures of an ancient galaxy born only two billion years after the Big Bang—easily reaching the limits sought by Spitzer. It has performed brilliantly in the search for “missing matter,” too. So far, the evidence seems to favor a universe that will keep on expanding forever—but the question isn't settled. With a 15-year lifetime, the Hubble may solve it yet.

Rigby and Kurdock have been watching these developments only as bystanders. Neither man professes to know much about astronomy. Neither was heavily involved in the Big Fix: their division of Perkin-Elmer had long since been bought by the Hughes Tool Corporation, which put Kurdock to work on other projects. Rigby took early retirement.

Today, when Rigby reminisces on his contribution to the Hubble Telescope, he still shakes his head and sighs. “I'll never see another mirror like that one,” he says.

Kurdock just laughs and says, "I hope I never do!"


 The universe is not only stranger than we suppose—it is stranger than we can suppose.

—J.D.S. Haldane