TMT Observatory Corporation
TMT Observatory Corporation
News Article | November 30, 2015
Snowcapped on its summit, fiery in its volcanic core, and flanked by basalt detritus and grassy plains, Mauna Kea is both serene and provocative; a finite object that evokes a sense of the infinite. It’s the tallest mountain in the world when measured from its undersea roots to its cindercone peaks, with a rich cultural history to match its immense size. Pilgrims have gravitated to its slopes for thousands of years seeking wisdom, discovery, enchantment, and a taste of the ethereal. It is also home to 13 sophisticated astronomical observatories that peer deep into time and space from their perches on its summit. Given the abundance of its natural and cultural gifts, perhaps it’s no surprise that over the last half-century, vehement disagreements over the “right” way to appreciate Mauna Kea have been brewing. This Hawaiian volcano has been dormant for 4,500 years, but it seems it can still inspire conflicts worthy of its pyrotechnic past. I had this in mind as I cruised across the Big Island’s obscenely gorgeous countryside in a silver Jeep Wrangler—an apex life experience if ever there was one—on a misty afternoon this past summer. After turning onto Mauna Kea’s switchback access road, I headed for the mid-level facilities and visitor center located on the Hale Pohaku plateau, at 9,200 feet of elevation. From there, Mauna Kea stretches up to almost 14,000 feet at its true summit of Puʻu Wekiu, but Hale Pohaku was as far as I could go. The summit road had been shut down for weeks. The closures were not due to natural forces, such as erratic weather or geological activity. Rather, the road had been blocked off by a dedicated group of protesters hoping to prevent the construction of a 14th observatory on the mountaintop: the massive Thirty Meter Telescope. The Thirty Meter Telescope, or TMT, is slated to be the largest telescope north of the equator by a huge margin. Provisionally scheduled to receive its first light around 2024 with its eponymous 30-meter-wide primary mirror, the facility will be able to take advantage of Mauna Kea’s pristine viewing conditions better than any observatory before it, exploring new cosmic vistas with spatial resolution 12 times sharper than the Hubble Space Telescope. The project is estimated to cost about $1.4 billion to construct, and is on track to be funded jointly by nonprofits such as the Gordon and Betty Moore Foundation, institutions such as Caltech and the University of California, as well as five sponsor nations: Japan, China, the US, Canada, and India. For some, the TMT represents the latest incarnation of Mauna Kea’s legacy as a potent portal to the worlds beyond our own, be they spiritual or cosmic. What better way to celebrate the legends of divine creatures atop the mountain than by constructing superpowered beings on its peaks capable of gazing deeper into space and time than ever before? For others, however, the TMT and its predecessors are unwelcome aliens that have desecrated the once-pristine peaks of the most sacred mountain on Earth. For decades, their pleas to cease development on Mauna Kea have fallen on deaf ears, and they have watched helplessly as the summit has transformed from an expanse of tranquil wilderness to a bustling hub of scientific research. Tension between these groups has simmered since the first observatories were erected on Mauna Kea in the 1960s, but on October 7, 2014—the day of the TMT’s groundbreaking ceremony—they finally boiled over. The celebration was cancelled after a group of about 50 protesters, mostly Hawaiians who believe the mountain should be used solely as a natural temple and religious site, blocked the summit access road. The main protest tent. “Aloha Aina” means love of the land. Photo: Becky Ferreira What began as a small community of local protesters has since evolved into a passionate movement, with international momentum and thousands of vocal followers. Celebrities like Game of Thrones star Jason Momoa—Khal Drogo himself—have shown their support for the cause, further boosting its profile. The upswing in attention also brought legal opposition to the TMT, which recently culminated in the temporary suspension of the telescope’s building permit by the Hawaii Supreme Court. Activists refused to vacate their temporary shelters on the mountain, even after Hawaiian Governor David Ige stepped in to support the TMT, resulting in dozens of arrests for trespassing. One particularly large protest on June 24 attracted about 700 protesters, many of whom dislodged boulders alongside the road, resulting in its closure and a full inspection of its safety and integrity. Two protesters were eventually convicted for petty misdemeanors committed during the demonstration. The situation escalated further when Hawaii County Police announced that fiber optic cables linked to the telescopes were intentionally damaged on June 24, resulting in $50,000 worth of repairs. The vandal has not been found. Undeterred by the arrests and negative press, the anti-TMT activists continued to occupy Mauna Kea. That’s where I found them when I parked the sweet silver Jeep at Hale Pohaku. Across the street from the visitor center, also closed due to the protest, stood a large tent adorned with a banner that read “Aloha Aina,” meaning love of the land. About two dozen activists had gathered in the tent to watch a livestream of a hearing about the TMT controversy, which was being held by the Department of Land and Natural Resources in Honolulu. They graciously invited me in and offered me banana bread, hot plate noodles, and juice as we watched the hearing play out on a series of different laptops, each of which was hastily replaced when it ran out of juice (no outlets on the mountainside, alas). I spoke to many of the protesters about their objections to the TMT, but was referred to Joshua Lanakila Mangauil when it came time to record. Protesters hold their hands in the shape of a mountain to symbolize protecting Mauna Kea during a news conference in Honolulu. Photo: Jennifer Sinco Kelleher/AP Photo “We have a saying in Hawaii,” he told me. “Before you look into space, you have to malama this place. You got to take care of this place.” A teacher with an expansive knowledge of the archipelago’s history, Mangauil has become one of the movement’s most prominent players. He considers himself one of many Hawaiian cultural practitioners, a term generally associated with reviving traditional indigenous practices in Hawaii, which have been suppressed by Western colonizers for many centuries. “Billions and billions of dollars to look around in space?" he said. "I admire the science. It is really cool. But it really is a bunch of 'ooh' and 'ahh.' It’s not necessity. You don’t need it. Especially at this time, when there’s so many things we need. People got to wake up and look at what’s happening to this planet.” This is a common argument against space exploration, and on its face, an ironic tack for a Hawaiian cultural practitioner to choose. After all, the Polynesians who first settled Hawaii some 1,600 years ago were arguably the most sophisticated astronomers of their era. Without their mastery of celestial navigation, the progenitors of the Hawaiian people would never have been able to colonize these remote islands randomly sprinkled in the middle of the Pacific. For his part, Mangauil is well aware of the irony, and told me that he is proud of the strong astronomical underpinning of Hawaiian traditions. “We’re star juice, hello!” he said, in what might be the most jubilant Carl Sagan paraphrase ever. “We link with many other stories around the world, with this concept of our race coming from the stars.” But in addition to their astronomical prowess, Hawaiians also have robust environmental traditions that protected them from sharing the fate of Polynesian settlements with less prescient resource management, such as the Rapa Nui of Easter Island. Under traditional Hawaiian kapu laws, Mangauil said, a person could even end up with the death penalty for killing a fish during the wrong season. “You’re talking to the people whose ancestors were the masters of natural resource conservation,” he told me. “I’m not saying we were perfect. I think we learned the hard way.” From the protesters' point of view, it is frustrating to watch as this hard-won wisdom, accumulated over millennia, is tossed out the window thanks to Western colonization. The rapid urban development of the past 100 years has undeniably wreaked havoc on the archipelago’s delicate ecosystems. Though the state only takes up 0.2 percent of US land area, Hawaii accounts for a whopping 75 percent of US plant and bird extinctions, and 25 percent of the nation’s endangered species. These alarming stats have saddled Hawaii with the nickname “the extinction capital of the world.” Mauna Kea is no exception, though the mountain’s biodiversity losses are mostly due to ranching and invasive species, not telescope construction. Still, the protesters fear that the mountain’s peaks—the holiest sites on the mountain, and the most coveted by astronomers—are in line to be the next victims of unchecked development. For the protesters, the science, interesting though it may be, simply does not justify what they call the “desecration” of Mauna Kea’s highest reaches, where only high-ranking Hawaiian priests were traditionally allowed to go. This is why the TMT has become such a powerful symbolic lightning rod, channeling much larger ideological issues that have been developing in Hawaii for centuries. It’s not as if the TMT will make or break Hawaii’s overall ecological health, but for the protesters, the telescope epitomizes the ideological fault lines between Western and indigenous land management. Add to that the weighty cultural significance of Mauna Kea as a family burial ground, archaeological site, and a time-honored place of religious worship, and you have a powder keg that was bound to ignite. For the protesters, Mauna Kea has always been the ultimate guardian for Hawaiians, and they are returning the favor. “[Mauna Kea] is our oldest sibling,” Mangauil told me. “We see it in our creation stories as not just as scientific creation, but as our genealogy.” “For us, our eldest living ancestor is the foundation for all of us to live. That’s why we’re here.” “All we want is to stop the TMT,” a young protester, who wished to remain anonymous, added. “[Mauna Kea] is heaven, and we want to protect heaven.” For millennia, people have speculated about the origins of celestial light. In Inuit legend, the first bead of daylight was delivered to the Arctic by a benevolent crow. In the Abrahamic tradition, God conveniently voice-activates the universe by declaring “let there be light.” Mangauil told me that the Kumulipo, a foundational chant in native Hawaiian religion, tells of the emergence of light from pō, the dark nothingness that preceded creation. These tales are vivid and beautiful, and they speak to the imaginative resourcefulness of humans seeking answers about the universe’s fundamental properties. That said, when it comes to rooting out the real origins of light, legends can’t hold a candle to a telescope. The telescope is the ultimate expression of human curiosity about light, the heavens, and existence itself. Over the course of 400 years, these instruments have rapidly evolved from the small, handheld spyglasses fashioned by Galileo to the mega-observatories, known as Extremely Large Telescopes (ELTs), currently in development. The TMT, if constructed, will be the the second largest ELT in the world, after the European Southern Observatory’s 39.3-meter telescope (E-ELT) in Chile’s Atacama Desert. Though the TMT and the E-ELT are separate projects, they are slated to come online around the same time, and the team leads coordinated with each other to ensure that they would be erected in different hemispheres to cover a broad, high-definition swath of skies. These new ELTs have the power to look across space and time to the first stars that ever shone in the universe, over 13 billion years ago. Millennia of folkloric riffing on the origins of light may have provided entertainment and solidified cultural ties, but the TMT is expected to be among the very first observatories—if not, the first—to actually witness the “let there be light” moment in cosmic history. “When you make the science case for these big telescopes, the first light [in cosmic history] comes up very quickly because it is a topic of much discussion,” physicist Mike Bolte, the associate director of the TMT, told me over the phone. “I’ve been in astronomy for 30 years now, and this has been a topic of great interest for all 30 years.” Up until this point, telescopes have only been able to capture light from younger, metal-rich stars like our Sun, which are called Population 1 stars, and older, metal-poor stars, called Population II. The progenitors of both families belong to the fabled Population III—the first stars, estimated to have burst into existence as early as 100 million years after the Big Bang. These stellar Adams and Eves have never been directly observed by astronomers before, though the elements they forged surround us to this day. “Theory says that these weren’t stars like our Sun, but were supermassive stars,” Bolte told me. “It’s thought that they evolved through their lives very quickly and blew up, seeding the universe with all kinds of heavy elements, like oxygen and iron, that we’re so fond of here on Earth.” “But nobody really knows,” he said, “so with the TMT, it will be the first time we will have the capability of looking all the way through space and time, to peer all the way back to that era when these objects were formed, and know for the first time what they were like.” The reason that the TMT will have such a keen eye for these exotic objects is fairly simple: It’s freakin’ enormous. For comparison, the largest ground telescope of its kind currently in operation is the Gran Telescopio Canarias (GTC) in La Palma, Spain, with a primary mirror measuring 10.4 meters wide, only about a third of the TMT’s diameter. Concept illustration of what the TMT will look like. Image: TMT Observatory Corporation/Wikimedia Commons “If you have a 30-meter telescope, you can get images that are three times sharper than a ten-meter telescope, and ten times sharper than a three-meter telescope,” Bolte said. “That’s why everybody’s so excited about these 30-meter class instruments.” While Population III stars are a major research target for the TMT, a facility this sophisticated is bound to revolutionize our understanding of practically anything it is pointed at. For example, one particularly exciting field that stands to gain a lot from the TMT is exoplanet research, especially the search for habitable worlds beyond the Solar System. “Extrasolar planets are very faint, so you need a big collecting area [to image them],” Bolte told me. “You need to be able to focus very finely, and that’s what these big telescopes are perfect for.” In particular, the TMT will be able to resolve some of these planets in such minute detail that so-called “biomarkers” in their atmospheres may be detected. The idea is to root out evidence of gases like oxygen, ozone, or methane, or other trace elements that suggest the possibility of life. It is spectacular to think that we are on the verge of creating an instrument so sensitive that it can capture photonic phantoms from the universe’s earliest days, and may even give us our first observational evidence of alien life. The most fundamental quandaries in both religion and science—where did the universe come from, and are we alone in it?—can be answered by the TMT and its ELT brethren. As the best site for astronomical observation in the northern hemisphere, Mauna Kea can play an integral role in unlocking these tantalizing mysteries. So why, some have asked, should the cultural traditions of a relative few be prioritized over breathtaking discoveries that belong to the entire human species? “As a Hawaiian, I recognize I am a descendant of some of the best naked-eye astronomers the world has known,” Chad Kälepa Baybayan, an accomplished captain of traditional Polynesian canoes, wrote in a West Hawaii Today op-ed. “It is culturally consistent to advocate for Hawaiian participation in a field of science that continues to enable that tradition and a field in which we ought to lead.” “I firmly believe the highest level of desecration rests in actions that remove the opportunity and choices from the kind of future our youth can own." One of the trippiest properties of telescopes is that they double as time machines. If we focus on a star located 2,000 light years away, we see it as it was 2,000 years ago. These spectral ghosts fill our skies, shining on though the objects themselves may be long dead. Astronomers have given this concept the eerily beautiful name “lookback time,” represented by the variable tL in equations. Like so many scientific terms, lookback time has a kind of poetic quality, one that seems to resonate especially well with the TMT controversy. Just as astronomers gaze into the cosmic past in order to contextualize the present and future, there is value in reflecting on Mauna Kea’s recent history, to better understand how so many people came to be fixated on clearing its summit. While the astronomers and the protesters may not agree about future development on Mauna Kea, I was surprised by how similar their perspectives were on its past. “Up until now, [telescope crews] ignored us,” John Roberts, a cultural practitioner who has opposed construction on Mauna Kea for decades, told me over the phone. “This new generation has better information and they are willing to get up there and make it public,” he said. “In the past, they wouldn’t allow us to do it, and they would write us off and continue to build, even though we protested.” Indeed, not only did the first crews ignore the early protests Roberts describes, there are reports that they were incredibly insensitive the the mountain’s cultural history. Family shrines and burial grounds were allegedly damaged or bulldozed. Zoning laws seemed as if they were rigged in favor of the telescope developers. The mountain’s religious significance was, and still is, laughed off. But times have changed, and for what it’s worth, many astronomers agree that the initial crews displayed an unfortunate tunnel vision when developing Mauna Kea’s summit. “When they first built the telescopes up there, I think due to ignorance and not due to bad intentions, there wasn’t a lot of attention paid to these cultural issues because they simply didn’t have a high profile back then,” Bolte said. “It is too bad, but it’s just the way it was.” Likewise, astronomer Doug Simons, who has worked with Mauna Kea’s Canada-France-Hawaii Telescope (CFHT) since it opened in 1979, and now serves as its executive director, thinks that this is a conflict that has been understandably percolating for decades. “I’ve watched it over 30 years go from a little opposition to what’s erupted in the past year, which is pretty intense,” Simons told me over the phone. “It’s complicated, and even those who oppose the TMT have a range of perspectives as to what they would like to see in the future for Mauna Kea.” Moreover, it’s not as if every Hawaiian cultural practitioner is against the TMT, or that every astronomer advocates for continued development on the mountaintop. “There are so many shades of gray in this, it’s mind-boggling to try to distinguish between all the different interests, interpretations, and perspectives about the summit of Mauna Kea,” Simons said. For their part, the TMT community has been working hard to find ways to make the TMT “seem like an asset, not just a distant thing that nobody benefitted from on the Big Island,” Bolte told me. “We’ve tried to make sure we understood as many viewpoints as we could,” he continued, referring to the larger TMT community. “That only happens when you talk to people.” Many astronomers share this optimism about nurturing the ongoing dialogue through regularly scheduled events like Department of Land and Natural Resources hearings, court cases, and community meetings like the “Common Ground” series of presentations held at Hawaiian public schools. The conversation has been encouraging so far despite the highly emotional nature of the debate for many of the people involved, said Simons, who frequently participates in these talks. “I really do believe in the ability of different interests in any particular spot on the ground to coexist,” he told me. “We have been doing it successfully for a while. I look for this sort of shakeup in perspectives to yield a greater degree of Hawaiian cultural incorporation into the future of Mauna Kea, but I don’t think it will be to the exclusion of astronomy. I’m convinced that they can coexist.” Along those lines, astronomers have begun to spearhead several initiatives aimed at involving the Hawaiian community in the research going on at the observatories, while also honoring Governor Ige’s resolution to decommission 25 percent of them to compensate for the construction of the TMT. Kupono Mele-Ana-Kekua, 35, of Kaaawa, Hawaii, blows a conch near the summit of Mauna Kea on Hawaii. Photo: Caleb Jones/AP Photo So far, three telescopes have been selected to be dismantled and removed over the next few years: the United Kingdom Infrared Telescope (UKIRT), the Hoku Kea Telescope, and the Caltech Submillimeter Observatory (CSO). Perhaps the most dramatic gesture of compromise occurred on November 24, when the University of Hawaii announced that the TMT will be the last telescope ever granted access to an undeveloped site on Mauna Kea. After so many decades of being ignored, these sentiments of goodwill are genuinely appreciated by some cultural practitioners, including John Roberts. “I don’t know if they’re ever going to resolve it,” he told me, “but I see that they’re trying. Hopefully, they come out winning for both sides.” On that note, both sides do seem to be scoring their fair share of wins. The summit access road is open again. Telescopes are being selected for removal. Charges against the majority of arrested protesters have been dropped. Construction on the TMT is currently stalled, but could resume as early as December 3. If and when crews push forward, it will mark the last time fresh ground will be broken for a new telescope atop Mauna Kea. A sign at the protester tent at Hale Pohaku. Photo: Becky Ferreira However, whether this will be enough to satisfy the most ardent protesters—or even the majority of the anti-TMT community—remains to be seen. “For me, I was always taught to practice what we call makawalu, which literally translates to ‘eight eyes,’” Mangauil told me. “You look at everything through eight eyes; multiple perspectives.” “Astronomy is going to have had 50 years on this mountain [in 2018],” he said. “Amazing discoveries have been found. But the land is still suffering.” For example, he pointed out that past observatories have spilled harsh chemicals like mercury, hydraulic fluid, and propylene glycol. A nasty septic backup at the visitor’s center in 2008 ended up dumping as much as 1,000 gallons of sewage onto the ground. Telescope crews duly reported these accidents to the Department of Health, and made efforts to prevent further pollution, but regardless, these spills have put people like Mangauil on their guard. On top of that, the anti-TMT protesters feel that the Big Island has been economically shortchanged by telescopic development. “Their claims from the beginning were that astronomy would save the economy,” he said. “That’s the same thing right now; they are saying that the TMT is going to save the economy. Well, you had 13 chances before and it didn’t do anything.” This particular charge is a little dicier to back up, as Mauna Kea’s observatories are a significant part of the Big Island’s economy. According to a 2014 report from the Economic Research Organization of the University of Hawaii, “total astronomy related spending in the state was $88,080,000 [while] astronomy activities generated $52,260,000 in earnings, $8,150,000 in state taxes, and 1,394 jobs statewide” in 2012. What’s more, the TMT has pledged to spend $1 million in rent annually, as well as an additional yearly $1 million for education scholarships to local students. This productive dialogue has inspired all sides to look back in time, both on the local scale of Mauna Kea and the cosmic scale of the universe. Astronomy is on the cusp of a new renaissance with the invention of ELTs, a thrilling opportunity to investigate the origins of our universe and the multitudes of worlds it contains. “We’re one little speck here on the Earth on the outskirts of one galaxy in billions of galaxies,” Bolte said. “It’s amazing that we know anything. The ability to explore—we’ve barely touched it with the facilities we have.” Meanwhile, the protests have also offered an opportunity to turn the lens back on our own planet. It’s incomprehensible that the same species capable of exploring such distant cosmic vistas can be so reckless about ransacking its own delicate homeworld. That’s an issue upon which we can all find the very valuable common ground of Earth itself. Indeed, as I drove back down the quiet mountainside, I couldn’t help but think of how many people regard Mauna Kea as a kind of metonymic stand-in for the entire planet. It is sometimes described as being a piko, or belly button—a symbol of birth, both volcanic and biological. “We see the mountain as a piko itself, both of the Hawaiian islands, and of the world,” Mangauil told me. Based on the depth of the discussion the TMT has sparked, I’m starting to think there might be something to this viewpoint. The mountain undeniably has a mystical gravity to it, one that attracts travelers from all over the world. If it becomes a catalyst for solving deep-rooted problems about our role on Earth and beyond it, well, let’s just say it wouldn’t be the first time the mountain has dispensed otherworldly clairvoyance to its visitors. Mauna Kea, as always, offers clear skies to those who seek them.
Sanders G.H.,California Institute of Technology |
Sanders G.H.,TMT Observatory Corporation
Journal of Astrophysics and Astronomy | Year: 2013
The Thirty Meter Telescope (TMT) will be the first truly global ground-based optical/infrared observatory. It will initiate the era of extremely large (30-meter class) telescopes with diffraction limited performance from its vantage point in the northern hemisphere on Mauna Kea, Hawaii, USA. The astronomy communities of India, Canada, China, Japan and the USA are shaping its science goals, suite of instrumentation and the system design of the TMT observatory. With large and open Nasmyth-focus platforms for generations of science instruments, TMT will have the versatility and flexibility for its envisioned 50 years of forefront astronomy. The TMT design employs the filled-aperture finely-segmented primary mirror technology pioneered with the W.M. Keck 10-meter telescopes. With TMT's 492 segments optically phased, and by employing laser guide star assisted multi-conjugate adaptive optics, TMT will achieve the full diffraction limited performance of its 30-meter aperture, enabling unprecedented wide field imaging and multi-object spectroscopy. The TMT project is a global effort of its partners with all partners contributing to the design, technology development, construction and scientific use of the observatory. TMT will extend astronomy with extremely large telescopes to all of its global communities. © 2013 Indian Academy of Sciences.
Ellerbroek B.L.,TMT Observatory Corporation
Journal of Astrophysics and Astronomy | Year: 2013
We provide an update on the recent development of the adaptive optics (AO) systems for the Thirty Meter Telescope (TMT) since mid-2011. The first light AO facility for TMT consists of the Narrow Field Infra-Red AO System (NFIRAOS) and the associated Laser Guide Star Facility (LGSF). This order 60 × 60 laser guide star (LGS) multi-conjugate AO (MCAO) architecture will provide uniform, diffraction-limited performance in the J, H and K bands over 17-30 arcsec diameter fields with 50 per cent sky coverage at the galactic pole, as is required to support TMT science cases. The NFIRAOS and LGSF subsystems completed successful preliminary and conceptual design reviews, respectively, in the latter part of 2011. We also report on progress in AO component prototyping, control algorithm development, and system performance analysis, and conclude with an outline of some possible future AO systems for TMT. © 2013 Indian Academy of Sciences.
Vogiatzis K.,TMT Observatory Corporation
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2014
Aero-thermal simulations are an integral part of the design process for the Thirty Meter Telescope (TMT). These simulations utilize Computational Solid-Fluid Dynamics (CSFD) to estimate wind jitter and blur, dome and mirror seeing, telescope pointing error due to thermal drift, and to predict thermal effects on performance of components such as the primary mirror segments. Design guidance obtained from these simulations is provided to the Telescope, Enclosure, Facilities and Adaptive Optics groups. Computational advances allow for model enhancements and inclusion of phenomena not previously resolved, such as transient effects on wind loading and thermal seeing due to vent operation while observing or long exposure effects, with potentially different flow patterns corresponding to the beginning and end of observation. Accurate knowledge of the Observatory aero-thermal environment will result in developing reliable look-up tables for effective open loop correction of key active optics system elements, and cost efficient operation of the Observatory. © 2014 SPIE.
Ellerbroek B.L.,TMT Observatory Corporation
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2014
The vertical profile of the mesospheric sodium layer varies significantly on a time scale of one minute. These variations can impact the random and systematic measurement errors of laser guide star Shack-Hartmann wave front sensors, particularly on extremely large telescopes. Sensor performance can be improved by selecting pixel processing weights matched to the sodium layer profile, assuming that the shape of the profile can be measured or estimated in real time. In this paper we describe the magnitude of these effects for the Thirty Meter Telescope AO system NFIRAOS. We review several existing approaches for measuring or estimating the sodium layer profile in real time. We then describe a new method for estimating the profile directly from the laser guide star wave front pixel intensities themselves, jointly with the subaperture tip/tilt measurements. The algorithm used for this purpose is based upon the multi-frame iterative blind deconvolution algorithm from image post processing: Subaperture tip/tilts and the sodium profile are estimated successively, bootstrapping the estimate of each quantity from the previous estimate of the other. We present promising initial simulation results on the potential performance of the algorithm, and suggest areas for future work. © 2014 SPIE.
Simard L.,TMT Observatory Corporation
Journal of Astrophysics and Astronomy | Year: 2013
The Thirty-Meter Telescope international observatory will enable transformational observations over the full cosmic timeline all the way from the first luminous objects in the Universe to the planets and moons of our own solar system. To realize its full scientific potential, TMT will be equipped with a powerful suite of adaptive optics systems and science instruments. Three science instruments will be available at first light: an optical multi-object spectrometer, a near-infrared multi-slit spectrometer and a diffraction-limited near-infrared imager and integral field spectrometer. In addition to these three instruments, a diverse set of new instruments under study will bring additional workhorse capabilities to serve the science interests of a broad user community. The development of TMT instruments represents a large, long-term program that offers a wide range of opportunities to all TMT partners. © 2013 Indian Academy of Sciences.
Stepp L.,TMT Observatory Corporation
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2012
The Thirty Meter Telescope (TMT) is a public-private-international partnership to build an extremely large optical-infrared telescope on the summit of Mauna Kea on the island of Hawai'i. This paper summarizes the design and predicted performance of TMT, and provides updates on the status of the development and prototype testing activities. TMT is currently in its preconstruction phase. The roles of the partner institutions for developing and delivering observatory subsystems are now well defined, the design work is maturing and plans for construction are in place. Current plans are for start of construction in April 2014, with first light including all 492 segments installed by the end of 2021. © 2012 SPIE.
Vogiatzis K.,TMT Observatory Corporation
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2011
The Performance Error Budget of the Thirty Meter Telescope (TMT) suggests that nearly one third of the total image degradation is due to aero-thermal disturbances (mirror and dome seeing, dynamic wind loading and thermal deformations of the optics, telescope structure and enclosure). An update of the current status of aero-thermal modeling and Computational Fluid-Solid Dynamics (CFSD) simulations for TMT is presented. A fast three-dimensional transient conduction-convection-radiation bulk-air-volume model has also been developed for the enclosure and selected telescope components in order to track the temperature variations of the surfaces, structure and interstitial air over a period of three years using measured environmental conditions. It is used for Observatory Heat Budget analysis and also provides estimates of thermal boundary conditions required by the CFD/FEA models and guidance to the design. Detailed transient CFSD conjugate heat transfer simulations of the mirror support assemblies determine the direction of heat flow from important heat sources and provide guidance to the design. Finally, improved CFD modeling is used to calculate wind forces and temperature fields. Wind loading simulations are demonstrated through TMT aperture deflector forcing. Temperature fields are transformed into refractive index ones and the resulting Optical Path Differences (OPDs) are fed into an updated thermal seeing model to estimate seeing performance metrics. Keck II simulations are the demonstrator for the latter type of modeling. © 2011 SPIE.
Vogiatzis K.,TMT Observatory Corporation
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010
In a previous study we had presented a summary of the TMT Aero-Thermal modeling effort to support thermal seeing and dynamic loading estimates. In this paper a summary of the current status of Computational Fluid Dynamics (CFD) simulations for TMT is presented, with the focus shifted in particular towards the synergy between CFD and the TMT Finite Element Analysis (FEA) structural and optical models, so that the thermal and consequent optical deformations of the telescope can be calculated. To minimize thermal deformations and mirror seeing the TMT enclosure will be air conditioned during day-time to the expected night-time ambient temperature. Transient simulations with closed shutter were performed to investigate the optimum cooling configuration and power requirements for the standard telescope parking position. A complete model of the observatory on Mauna Kea was used to calculate night-time air temperature inside the enclosure (along with velocity and pressure) for a matrix of given telescope orientations and enclosure configurations. Generated records of temperature variations inside the air volume of the optical paths are also fed into the TMT thermal seeing model. The temperature and heat transfer coefficient outputs from both models are used as input surface boundary conditions in the telescope structure and optics FEA models. The results are parameterized so that sequential records several days long can be generated and used by the FEA model to estimate the observing spatial and temporal temperature range of the structure and optics. © 2010 Copyright SPIE - The International Society for Optical Engineering.
Agency: NSF | Branch: Cooperative Agreement | Program: | Phase: Partnrshp Planning Solicitatn | Award Amount: 750.00K | Year: 2013
The Thirty Meter Telescope (TMT) Project is designing and planning to construct and operate a 30-
meter diameter optical/infrared telescope with fully integrated adaptive optics to lead the next generation
of telescopes with observation at the diffraction limit of its large aperture. TMT science goals address the
recommendations of the last two US decadal surveys of astronomy and astrophysics that gave high priority to the science that can be accomplished by a giant segmented mirror telescope. Sited on Mauna Kea, Hawaii, TMT will be the only such telescope in the northern hemisphere. TMT is a collaboration of California Institute of Technology, University of California, the Association of Canadian Universities for Research in
Astronomy, the National Astronomical Observatory of Japan, a consortium of Chinese institutions led by
the National Astronomical Observatories of the Chinese Academy of Sciences, and institutions in India
supported by the Department of Science and Technology of India.
The five-year planning activity supported by this award will lead to a US astronomy community science plan, an integrated science and education plan, proposals for US groups to collaborate in TMT science instruments, a US operations plan, and a US TMT data management plan. Activities under this award will include a series of joint TMT US-international Forums and annual workshops and Town Halls at the annual meeting of the American Astronomical Society. Three representatives of the NSF-supported astronomy community will become members of the TMT Collaborative Board, assuring a US role in shaping the project and its implementation. A US TMT Science Advisory Group will engage the US community in developing the science plan, and three members of the Group will join the TMT Science Advisory Committee, assuring input by the US community in guiding the TMT science program and interaction with other TMT astronomy communities. A TMT Education and Public Outreach Advisory Board will focus the broad expertise and interest in stakeholder communities in developing an integrated plan to leverage TMT science in education, work force development and other broader impacts of TMT in society.
TMT will engage the US astronomy community in their formulation of plans to exploit TMT scientific
opportunities and to integrate TMT into the US optical/infrared observing system. By joining with TMT,
the US astronomy community will be able to build on the substantial scientific synergy of national and
international observatories already located on Mauna Kea and enjoy new opportunities to collaborate with
the international astronomers participating in TMT. TMT will also benefit from the expertise of the US
astronomy community in defining TMT technical systems and future science instrumentation.
As a leading national science resource, TMT will contribute excitement to its host community in
Hawaii, as well as national significance in catalyzing public interest in astronomy, science and
technology. Building upon the projects existing plans in Hawaii, TMT will engage the US community
and education stakeholders in planning a broader US education and work force development program
under the guidance of an Education and Public Outreach Advisory Board. Sited in the center of the Pacific Ocean, TMTs unprecedented observational power will serve as a catalyst for collaboration among scientists in the Pacific Rim astronomy communities.
In response to solicitation NSF 12-526, NSF will engage with the TMT Project to plan a partnership model for the TMT Observatory which, depending on circumstances, the NSF may join at some later date.