The Mirrors of Mauna Kea : Daringly Different, Keck Observatory’s Multifaceted Telescope Will Look Back to the Origins of the Universe
Winds have been howling over the 13,794-foot summit of Mauna Kea for almost a week, frequently gusting above 100 m.p.h. A transmitter atop the dormant volcano blew down the night before, severing communications with workers at the construction site. A repair crew is refusing to make the long, twisting drive up the mountain under these conditions. More problems. Jerry Nelson props his bare feet on a computer table, picks up the phone and dials Terry Mast, a colleague on the W.M. Keck Telescope project and an old friend. What now? Mast wants to know.
The computer program that controls a key part of their revolutionary telescope is screwed up, Nelson complains, and the software engineers have concluded that they can’t fix it--their own program! “I don’t understand how people who built something can say, ‘It’s broken and we can’t fix it,’ ” Nelson says, rounding off the sharp edge in his voice with a fatalistic laugh. He is a consummate scientist, and nothing bugs him more than something that doesn’t make sense. The problem with the Keck Telescope atop Hawaii’s Mauna Kea clearly falls into that category, joining the thousands of other setbacks that have given Nelson headaches to match his mountain.
There must be days, I suggest, when he wishes he had never set his sights on something the experts said could not be done. A boyish grin spreads across his face. No, he says convincingly. There are no such days.
The 49-year-old physicist in the faded aloha shirt, looking like an aging surfer in his office at Kamuela, near the Big Island’s Kona Coast and a two-hour drive from the summit of Mauna Kea, has faced adversity before. A few years ago, Nelson stood almost alone against the world of astronomy. He claimed he could design and build the world’s largest telescope, far bigger than what was thought feasible.
He aspired to change the state of the art, to abandon the traditional single-mirror reflecting telescope epitomized by the famous 200-incher atop Mt. Palomar in northern San Diego County. He would build instead a telescope of 36 hexagonal mirrors, each 1.8 meters in diameter, fitted together in a pattern like a honeycomb and computer-controlled so precisely that they would work as if they were a single mirror 10 meters in diameter. That would be twice the diameter and four times the power of the Hale Telescope at Palomar.
It would be the most complicated ground-based telescope ever built, but if it worked, it could produce the sharpest images ever from the distant reaches of the universe.
Most of his colleagues said he was nuts.
In the 1980s, when Nelson began to act on his dream, it didn’t help that he still bore a teen-like youthfulness, hardly the image of a scientist who could lead a technological revolution. Confident almost to the point of cockiness, he engaged his detractors with disarming poise, quickly admitting that he did not have all the answers. Not then at least. But now the W.M. Keck Observatory is expected to be operational by the first of the year.
Nevertheless, he has his critics. One of the nation’s top telescope designers, who demanded anonymity, once described Nelson as an “arrogant fool.” Nelson’s telescope is so complex, the designer insisted, that it will not work. And in the end, he said, the nearly $200 million spent on the observatory will be wasted.
There is no way Nelson could have foreseen just how rough a course he had set as a young scientist seeking to make his mark on the world. Before it would end, he would see his project jeopardized by the death of a benefactor and claims of flawed work by contractors thought to be the best in the world. Most difficult of all, while Nelson struggled to keep his mind on the dream, his wife was dying.
JERRY NELSON’S AIM WAS TO BUILD A TELESCOPE so powerful it could peer back through the dimension of time, toward that point, perhaps 15 billion years ago, when most astronomers and physicists believe the expanding universe was born in a big bang of creation. Dim and distant objects hold secrets of the evolution of the cosmos. Precise measurements of their chemical composition, age, distance from Earth and evolution should provide the data that scientists use to try to resolve mind-bending questions: What’s beyond our little solar system, beyond our Milky Way galaxy, out there in the dust-obscured or empty stretches of space? How did it begin, and how will it end?
Great telescopes are like time machines because they look so far into the distance that they see objects as they used to be. The Keck Telescope promises to let us look more deeply, capturing light from the faintest specks in the sky, stars and starlike objects that formed when the universe was very young. It will be a leader, Nelson says, “the most productive era in the history of astronomy.”
The Keck Observatory is to be the crown jewel atop Mauna Kea, a stark astronomical cathedral that towers nearly 14,000 feet above the Pacific. Tall, reddish cinder cones from past volcanic activity dot the bleak summit. Nothing grows on top of the mountain, which is covered with snow in the winter and has an average temperature just above freezing, a world away from the lush tropical forests below.
An array of telescopes decorate the mounds of Mauna Kea’s summit, their white domes lifeless in the bright light of day. They will come alive in the evening, when the dark sky offers a clear view of the heavens, and astronomers from around the world will come here to pose their questions and test their theories. There are 10 observatories on the summit, and more are planned. Most are American, but European and Japanese institutions also have telescopes here.
Work on the Keck Observatory started eight years ago. Under the direction of University of California and Caltech scientists and engineers, three of five instrument packages have been installed in a program that will allow the telescope to record electronic images, similar to photographs, emitted by heat-producing sources. Most promising are the infrared rays of these sources because their longer wavelengths will allow the telescope, in effect, to look around corners, penetrating the dust that hides the center of the Milky Way galaxy. Astronomers hope this will help them determine whether a black hole lurks there, supplying the gravitational pull that causes our galaxy to spin. It will also help them study the birth of stars, a process normally shielded by cosmic dust.
One of the Keck’s first assignments will be to join the search for planets circling stars similar to our sun. No ground-based telescope will ever be able to photograph the planets of alien solar systems because the brilliance of their stars would overwhelm their images; it would be like trying to see a match in front of a searchlight. However, other data could deliver the proof. The planet Jupiter, for instance, is a billion times dimmer than the sun, but it is heated by the sun’s rays, and that energy rebounds as infrared light. The Keck’s instruments should be able to tell whether other planets--and possibly other life forms--are common in the cosmos if they can determine that light from other stars contains an infrared component emitted only by orbiting planets.
Whatever it achieves, the Keck Observatory will make a mark in astronomy, and it will continue a powerful tradition of California-influenced advances in the field. In the 1920s, a cluster of pioneering telescopes atop Mt. Wilson, north of Pasadena, built by the Carnegie Institution and Caltech, marked the beginning of big-time astronomical research in the state. And Caltech scientists crowned the advances with the erection of the Hale Telescope at Mt. Palomar in 1948. The Hale is still ranked as the most productive telescope in the world. Its 200-inch mirror was surpassed in size in the 1970s when the Soviets built a mirror six meters (236 inches) in diameter for the Bolshoi Telescope on Russia’s Mt. Pastukov, but that instrument has never performed satisfactorily.
In recent years, smaller telescopes in settings less infused with damaging city light have taken the lead, places such as Mauna Kea and Kitt Peak outside Tucson. But the Hale Telescope has delivered much of what astronomers now know of the universe. And many experts said no larger one could be built.
IN THE LATE 1960S, JERRY NELSON WAS A young physicist at UC Berkeley, a doctoral candidate already growing weary of his chosen discipline: high energy physics. Teams of scientists, sometimes numbering in the hundreds, are required for the atom-smasher experiments used to study subatomic particles, the meat of the field. It was not the right spot for a loner.
“It was interesting stuff, but I saw where it was going,” recalls the affable Nelson. So he moved into astronomy research, where he could work alone or with a handful of colleagues. “I had more control over my destiny,” he points out.
Nelson began focusing on astronomy just as the University of California system found itself at a crossroads. UC had always considered itself a leader in the field, partly because of its operation of the Lick Observatory on Mt. Hamilton outside San Jose, but increased light pollution in the Bay Area was undermining the Lick’s three-meter telescope. Other institutions were planning to build bigger telescopes in remote areas, and UC realized that it would fall behind if it did not make a move. It was 1977, and Nelson, then 33, was appointed to a committee to study the university’s long-term future in astronomy.
“We were called the Graybeard Committee” because most of the members were senior astronomers, says Robert Kraft, then director of the Lick Observatory and now an astronomer at UC Santa Cruz. Nelson was chosen because he had impressed his colleagues with his knack for innovation.
Many astronomers thought the Hale Telescope at Mt. Palomar, with its 200-inch mirror, was the largest that could be built because glass tends to deform under the pull of gravity and a bigger mirror would sag and distort images. “So I went off and looked into that,” Nelson says. “And I came back and reported to the committee that I thought it was technically feasible and economically quite reasonable to build a 10-meter telescope. They said, ‘You’re nuts. Get out of here.’ ”
Nelson admits today that the committee members had no reason to expect that someone with his limited experience could have the answers, but he had spent several months studying the underlying physics and engineering of large telescopes. What was needed, Nelson had concluded, was a radical approach, a different kind of mirror. A concave mirror is the heart of the traditional reflector telescope, receiving light from celestial bodies and focusing the image onto photographic plates or some other recording device for study by astronomers. Nelson calculated that several mirrors could be computer-controlled so precisely that they would act as one. Such an array of mirrors would be many times lighter than a 10-meter-wide sheet of glass. It would be easier to maneuver, and the concave mosaic could be curved so steeply that incoming light would be focused relatively close to the mirror, making it possible to build a 10-meter telescope in an observatory no larger than the Hale at Palomar. That would be about half the size of the facility required to house a mirror made of one piece of glass of that magnitude, and that would keep the cost down substantially, Nelson reasoned.
He convinced Terry Mast and physicist George Gabor that his design would work, and in 1989 a handful of telescope experts--a small fraternity by any measure--gathered in a Berkeley auditorium to hear this outsider of unproven mettle lecture on how to build the world’s greatest telescope. The presentation was audacious, an assertion that 36 mirrors could act as one. Not surprisingly, only a few caught Nelson’s faith that day.
“They told us we couldn’t electronically glue together broken pieces of glass,” says Gabor, who had designed other computer-controlled systems for the Lawrence Berkeley Laboratory. He was given the task of developing the technology to do just that.
Radio astronomers, who study radio-wave emissions from various cosmic sources, had used segmented designs for years, so the concept was not new. But the engineering tolerances for an optical telescope would have to be tens of thousands of times more stringent than for radio telescopes, and that requires a level of perfection that many thought impossible.
Nelson was not rattled. But it was a while before the idea took off--even for those on the UC committee. “The process we went through was that I explained my ideas to the committee, and they said, ‘Yeah, that’s very interesting, do some more work,’ ” Nelson relates. “So I did more work, went back and said, ‘OK, here’s more details. Here’s where the problems are, here’s where we don’t know how to do it yet, and here’s how I think it ought to be done.’ ” Slowly, Nelson began to win converts.
There seemed to be no alternative if the current generation of telescopes was to be surpassed, save for the exotic idea of a space-based instrument free from the distortions of Earth’s atmosphere. That concept came to fruition in 1990, when the National Aeronautics and Space Administration launched the Hubble Space Telescope, but the Hubble has proved to be one of astronomy’s most celebrated failures. It has done some important work and promises to do more, but the results have fallen far short of expectations because of technical flaws, including an incorrectly ground primary mirror. The cost to NASA--about $2 billion to build, launch and operate the space telescope--could have funded dozens of large, ground-based telescopes. And for its $2 billion, NASA has a telescope derisively nicknamed “The Rubble.” BIG SCIENCE MEANS BIG BUCKS, and even a huge state university doesn’t have the funds for high-priced, high-risk dreams. “Nobody to my understanding ever has any money in the university system,” Jerry Nelson says, looking back on the struggle to underwrite the observatory on Mauna Kea. “What they do is go look for somebody who has money.”
In the early 1980s, the University of California found its angel in the widow of Max Hoffman, who had made a fortune in the imported car business in New York. Marion O. Hoffman had read about Nelson’s dream and it seemed to be a perfect project for her late husband’s $60-million estate. She wanted to create something that would reflect his interest in high technology.
But the Hoffman estate could not fully fund the telescope, so UC offered Caltech a junior partnership in the project--if the Southern California institution could make up the shortfall. Meanwhile, UC President David Saxon, a physicist who had supported the project, had been replaced by David Gardner, an educator who was not as eager to commit the university to such a costly venture unless he was assured that no state funds would be needed. Gardner wanted to wait until Caltech came aboard before accepting the Hoffman gift. A year and a half passed before Gardner and Hoffman met and the university agreed to accept the estate. The next day, Hoffman unexpectedly died.
Her heir, a sister, was less enthralled with the telescope idea, clearly indicating she wanted the money to go elsewhere. Anticipating a legal fight, the university gave up on the estate, and for a while it seemed Nelson’s dream might have died with Marion Hoffman. But in the meantime, Caltech officials had found a benefactor in Howard Keck, an oil magnate and Caltech trustee fascinated by the telescope proposal. Keck is chairman of the W.M. Keck Foundation, one of the country’s largest, which was established by his late father, William M. Keck Jr., the founder of Superior Oil Co. In 1985, Keck said the foundation would fully fund the project, but he wanted control in the hands of Caltech, not the University of California.
Keck’s generosity created an awkward situation, according to several sources involved in the negotiations. UC could have lost out on its own design, but Caltech officials are sensitive to intellectual rights and did not want to just take over the project. Months of discussions ensued before Keck and the two institutions reached a compromise. It would be a joint project with UC and Caltech sharing 90% of the telescope’s precious viewing time. The remainder would go to the University of Hawaii, the landlord for Mauna Kea.
Work is under way on a second Keck Telescope that will be adjacent to the first one. Problems with mirror fabrication ate into the financial reserve for Keck 1, raising the cost to $94 million, barely within budget. Keck 2 is expected to cost about $1 million less. The Keck Foundation put up $70 million for Keck 1 and it is obligated to pay 80% of the costs of Keck 2, an exact copy of its sister telescope, in effect providing each institution with its own 10-meter telescope and doubling the viewing time of the observatory. The balance of funding for the projects will come from private funds raised by Caltech. UC is paying for the operation of the telescopes.
Unlike so many great ideas that die on the funding table, the Hoffman Telescope had survived, although reincarnated as the Keck Telescope. But Nelson and his colleagues soon learned that getting the money was the easy part, and they would need a steady hand at the helm.
GERALD SMITH GAZES OUT of his office and across the rolling hills of Kamuela. Yes, he concedes, the Keck Telescope would cap his long career. It hasn’t been easy, he admits, and technical problems have put it two years behind schedule. But, he says, he would do it all over again.
Smith is a wiry scientist who could wither Goliath with an icy stare. A veteran of some of NASA’s most successful programs, including the space probes Mariner, Viking and Voyager, the soft-spoken engineer had already been involved in the construction of one major telescope, NASA’s three-meter infrared instrument on Mauna Kea, when he was chosen as Keck project manager.
Smith is thorough, a characteristic learned the hard way. In the 1960s, when he was as green as Hawaii’s tropical forests, he was an electrical engineer on Ranger 6, a robotic probe designed to provide close-up photos of the moon’s surface. It was his first NASA assignment.
“It failed,” the silver-haired engineer says. “It crashed into the moon without the cameras’ ever coming on. But it was a lesson I never forgot. Once you’ve been through a project that failed, it makes you much more sensitive to things that you don’t understand.”
It teaches an engineer to watch out for anything that can go wrong, and those who work with Smith in Hawaii say they do their homework carefully before meeting with the quiet man in the corner office. There have been times when the modernistic headquarters at Kamuela shook with closed-door confrontation. Gerald Smith and Jerry Nelson, both strong-willed and confident men, are frequent combatants.
“Jerry is very enthusiastic, very positive, very strong-minded,” Smith says. “Sometimes that causes friction. We have had occasions where we have disagreed, and we have disagreed pretty strongly at times. He likes to have his way, and I like to have my way.”
For a while, the fire went out of the relationship. Nelson’s wife died last year after a long illness, leaving him the single parent of a son in high school and a daughter at Stanford University. It was a time of immense stress for the family, and Nelson seemed to lose interest in his work, friends say. But earlier this year, the flames began to burn again, rekindled as Nelson struggled to get on with his personal life as well as his work.
From the start, the two key men of the Keck project knew that they had to come up with the best mirrors ever built. No telescope is better than its mirror. The goal was to make the Keck’s multiple mirrors so good that the only degradation in the image would be caused by atmospheric distortion, not imperfections in the glass. Therefore, the 36 mirrors had to be perfect, polished and controlled to such a degree that when the 36 individual images of a star were “stacked,” they would appear as a single, brilliant image.
Keck engineers turned to Itek Optical Systems of Cambridge, Mass., a veteran Pentagon contractor with a reputation for excellence, to make the mirrors. But Itek, which was accustomed to the secrecy of military contracts, and Nelson and his colleagues, who were used to the openness of the academic community, did not mesh well. “We found it difficult to work with the Itek people,” the astronomer says.
Furthermore, tests revealed imperfections--rough spots--in the Itek mirrors, Nelson and Smith say. As tension grew between the two camps, it became clear that the undertaking could be jeopardized. The dreamers who had come up with the revolutionary design were forced to accept the possibility of unsolvable problems. “That was really a low point,” Nelson says grimly.
However, about that same time, Eastman Kodak Co., which manufactures precision optics for the military, was developing a technology called ion figuring. Under this process, a beam of electrically charged atoms is fired onto a surface, blasting off unwanted material. Kodak recognized that if the ion beam could be precisely manipulated, it would be possible to slowly remove glass one atom at a time, like a fine spray of water hitting a pile of sand. This could correct the imperfections.
One of the disappointing mirrors was taken from Itek and given to Kodak for experimentation. After several months, the process was fine-tuned. Itek continued to polish some of the Keck mirrors, but others were sent to Tinsley Laboratories in Richmond, Calif., for polishing and then reshipped to Kodak’s plant in Rochester, N.Y., where ion beam technology perfected them, smoothing out the rough spots one atom at a time.
IT HAS BEEN A DIFFICULT drive up the steep slopes of Mauna Kea, and Nelson seems almost giddy as he wrestles the truck along the gravel road leading up to the observatory. It is a bitterly cold morning, and the clouds are below us. The sky is incredibly blue, and the glittering white domes create an atmosphere that seems sacred. This is the holy of holies for astronomers, the sanctuary where they seek to answer the hardest questions of all.
While the Keck Observatory is expected to remain without peers for some time, the competitive drive to build even greater telescopes will eventually bring change. However, there will be no more observatories quite like the Keck. Its level of technology alone makes it unique. It seems a little less romantic than its predecessors, for instance. Unlike the lonely pursuit of earlier astronomers, those working at the Keck will not have to take the long drive up a mountain and sit in a darkened room while their telescope probes the heavens. Instead, they will remain in a sanitized control room at the headquarters building in Kamuela, monitoring computers that will run the telescope. Aided by only one or two technicians, the astronomers will punch keyboards and stare at video screens in a room that looks like thousands of other computer centers in banks and insurance companies across the world. High atop Mauna Kea, which can barely be seen from Kamuela, the Keck’s great dome will open and the telescope will track the heavens, controlled by unseen hands and impersonal computers.
Of the several large telescopes now under development, none will use segmented mirrors. Smith and Nelson say they are baffled by that. They feel they have proved the validity of the design, but others are less sure. It may work well in the beginning, some argue, but the Keck will require more effort--and more money--to keep its complex system working. Most new telescopes will use single, flexible mirrors. European astronomers plan to build four eight-meter telescopes in Chile, a project that could rival the Keck. And other new telescopes are springing up on mountains from Arizona to the Canary Islands--none like the Keck. So the world of astronomy is still waiting to see if a young dreamer was right when he claimed he had a better idea.
Nelson shows no sign of fatigue from the drive up. The astronomer bounds out of the truck and within minutes he is climbing up the tubular support system that holds the 10-meter mirror in place. He carries a small device that will allow him to measure the height difference between the mirror segments, and he intends to see firsthand whether they are aligned the way the computer tells him they are. Hanging by his arms from the support system 100 feet above the concrete deck, Nelson whistles while he works.
It is a task he could have assigned to a technician. But he wanted to do it himself. After all, this is his baby.
