Astronomy Foes Join Forces to Build Giant Telescope

Public and private sectors of US ground-based astronomy have teamed up to design a 30-meter optical-infrared telescope. The alliance was formed to bolster the chances of realizing the project, but it could also herald a thawing of relations between the traditional rivals.

On 11 June, the Association of Universities for Research in Astronomy and the California Extremely Large Telescope (CELT) Development Corp, a partnership of Caltech and the University of California (UC), agreed to raise a total of $70 million for a detailed design of a 30-meter telescope (TMT; the private partners call their preexisting project CELT, and the public partners call theirs the Giant Segmented Mirror Telescope, or GSMT). AURA oversees public, or federally funded, optical observatories, and the CELT group is private, with funding from state and private sources. Canada and the CELT group initiated a similar bilateral agreement on the same day. The grand plan is to refine the design, choose a site, raise more money, and have the telescope up and running in time to work in tandem with the James Webb Space Telescope (JWST), the Hubble Space Telescope’s successor, which NASA plans to launch in 2011.

Just as the Kecks and other ground-based telescopes complement the HST, astronomers want to use the TMT to do spectroscopy of very distant objects imaged by the JWST. Besides the unpredictable discoveries, the main goals for the TMT are to study the formation of galaxies and stars and to directly observe extrasolar planets. “Assuming the telescope has extraordinary image quality and diffraction-limited images,” says Rolf Kudritzki, head of the University of Hawaii’s Institute for Astronomy and chair of the GSMT science working group, “we can follow the production of elements, and how they got into the intergalactic medium, and how the intergalactic medium enriches in chemical composition. We can follow the merging of the first building blocks to form larger entities. We can follow the evolution of the universe over 12 billion years.”

The TMT would have a diameter three times larger than any existing optical telescope. “No leap this big has ever been made. It’s extremely ambitious,” says astronomer Richard Ellis, Caltech’s CELT representative. Estimates for the TMT start at $700 million, with annual costs put at $30 million to $70 million. “Everybody is recognizing the same thing, that public and private [observatories] have to pool resources to tackle new projects,” says AURA chief William Smith. “The primary rationale is probably financial, but in most cases there is a technical benefit.”

Culture shift

If joining forces is the best hope to muster money, it is also likely to shake up the astronomy community. “We are probably witnessing the end of the era of private supremacy,” says Pennsylvania State University’s Lawrence Ramsey, project scientist for the Hobby Eberly Telescope (HET). “Only the federal government—only NSF—has pockets deep enough to be a substantial partner in a TMT. NSF is the indispensable partner,” says Matt Mountain, director of Gemini. The US 50% share in Gemini, together with the National Optical Astronomy Observatory (NOAO), makes up the public part of the new TMT partnership. “We have to go through the same culture shift that particle physics went through in the 1960s,” Mountain adds. “That’s why there is so much passion here—it’s basically changing a way of life.”

US ground-based optical astronomy is unusual in that it’s a hybrid of public and private observatories. Rivalry between the two camps stretches back nearly a half century, to when AURA came on a scene that had been mostly populated by privately owned telescopes. Today, roughly two-thirds of the US share in big telescopes worldwide is private, and one-third is public (see the table on page 23). The main cooperative efforts between the public and private observatories so far are the 4-meter—class WIYN and SOAR telescopes and new programs in which NSF pays for instrument and adaptive optics development at private facilities in exchange for observing time for the wider astronomy community. The telescope consortia both include NOAO, along with the Universities of Wisconsin and Indiana and Yale University (WIYN) and Brazil, Michigan State University, and the University of North Carolina, Chapel Hill (SOAR).

Generally, private observatories see themselves as less bureaucratic, quicker to respond to scientific opportunities, more flexible in allotting observing time, more efficient in their use of money, and, not coincidentally, more alluring to the best scientists than are public observatories. A particular sore spot is hard-to-raise operating funds: Astronomers at private observatories often say they could get a better science return from the public observatories’ NSF money. For example, Ellis notes that the Kecks—the two 10-meter kings of optical astronomy built by the CELT team—cost less to run than Gemini, the 8-meter twins that are the pride of the public observatories. Even allowing for differences such as Gemini being an international collaboration split across two hemispheres, he says, “it’s clear that the national resources have been much more generous than what’s available for privates.” As a consequence, he adds, astronomers at private observatories must be more self-reliant than those at public ones, which have larger staffs.

For their part, astronomers and managers at the public observatories point to the hallowed principle of providing telescope access to the entire astronomy community. They admit that NOAO has suffered an identity crisis in the past few years. But it is reclaiming a leadership role in optical and infrared astronomy, says the observatory’s director, Jeremy Mould. “I think people are beginning to see the emergence of an effective national observatory.” Adds Mountain, “Caltech and UC asked us to partner. That tells you that the public side is on a par with the private side. Caltech and UC are used to being a decade ahead. Gemini is what made us be players.” In addition to access to federal money, Mountain says, the public side of the TMT partnership brings expertise in wind buffeting and adaptive optics and well-established relationships with Chile, a possible host for the telescope. (Mauna Kea in Hawaii and San Pedro Mártir in Mexico’s Baja California are the other sites under consideration.)

Just how the public—private partnership will work in practice is still fuzzy. Both sides expect that everything from designing the telescope and its instruments to allocating observing time will be divvied up in proportion to the partners’ contributions. At the same time, the sheer cost makes it likely that telescope time will be distributed in a queue-mode, the way the public facilities do it now. “We are still feeling our way,” says Joseph Miller, director of Lick Observatory and UC’s CELT representative. “The question is, How will it work? And will it work?” One issue, for example, is how to stay nimble while also incorporating the more cumbersome decision making process of a federally funded project. “There are days when I really worry about it,” Miller says. But, he adds, “if we can make this work, it will be a good thing.”

‘Like boiling gasoline’

Despite broad support for closer public—private interactions, not all astronomers are thrilled with the AURA—CELT agreement. “Defusing this have—have-not business would be a huge plus,” says Frank Bash, director of the University of Texas’s McDonald Observatory, referring to the perception that astronomers are split according to whether or not they have access to private telescopes. “But it was way too early to choose a project. Others would have liked to compete.” Bash was one of fifteen astronomers, most of them at AURA member institutions and four of them directors of private observatories, who sent AURA’s Smith a letter of protest. In it, they wrote that AURA’s tying the knot with CELT without first evaluating other concepts for extremely large telescopes “precludes fair and open competition.” The letter’s tone, says Bash, “was reasonably low key. But it could flare up. It’s like boiling gasoline.”

AURA counters that both building a TMT and finding partners to do so were top priorities for ground-based astronomy in the National Academy of Sciences’ 2001 Astronomy and Astrophysics in the New Millennium decadal survey. Says Smith, “There are other telescope groups that have alternatives. There are other ways to spend money and attention. But we chose to follow the decadal survey.” The other concepts—notably a 25-meter scaled-up HET and a 20-meter version of a Magellan telescope, both under discussion by private groups—are completely different, he says. “There are only two credible designs for TMTs on the planet,” adds Mountain.

In any case, AURA is careful to specify in the agreement that its research contributions should “directly benefit other large aperture telescope efforts.” Accordingly, the public partners expect to work on such broadly applicable things as mirror coatings, detectors, advanced gratings, and site characterization. More than keeping open the possibility of involvement in other 30-meter—class telescopes, AURA has its eye on collaborating later with Europe on an even larger telescope.

The public—private partnership in the US, meanwhile, brings urgency to Europe’s decision on whether to build a 30-meter—class telescope or go straight to a 50- to 100-meter one. “The fact that [AURA and CELT] have joined makes their project more likely to succeed. It also makes a European one more likely to succeed,” says Roberto Gilmozzi, director of the European Southern Observatory’s Very Large Telescope and principal investigator for ESO’s 100-meter Overwhelmingly Large Telescope (OWL). “The natural timescale of OWL is 15 years. If CELT moves ahead in 10 years, the [European astronomy] community would ask us to do something faster. The biggest pressure is that Europe not lag behind.” The new partnership, adds Tim de Zeeuw of Leiden University in the Netherlands and a member of both the AURA board and the ESO council, “has stimulated the ESO to look carefully at its own future planning. Do we compete? Or do we at some point join forces? “