The Hubble Problem: Scientists Try To Pick Up The Pieces

As the shock over the mirror defect in the Hubble Space Telescope begins to wear off, some 1,000 astronomers, many of whom had anticipated funding from NASA and all of whom expected unprecedented pictures and data from the $1.6 billion instrument, are trying to salvage their research plans. Scientists at NASA headquarters in Washington D.C., the Space Telescope Science Institute (STSI) in Baltimore, the Goddard Space Flight Center in Greenbelt, Md., and here throughout the world are analyzing results of extensive testing of the telescope while re-evaluating their projects so that observation time on the telescope can be rescheduled and funding can be reworked. At the same time, astronomers and administrators alike are trying to squeeze as much good science as possible out of the scope in its current state. Only the fine guidance sensors used to point the Hubble telescope and measure star positions are not affected by the flaw in the primary mirror. Affected to some degree are five of its six major devices--the wide-field camera and planetary camera (WF/PC), faint object camera (FOC), high resolution spectrograph (HRS), faint object spectrograph (FOS), and the high speed photometer (HSP). Of all five, the WF/PC is the hardest hit by the flaw. "It is only able to do 15 to 20 percent of the programs planned for it," says Ray Villard, spokesman for Space Telescope Science Institute. Unfortunately, 40 percent of all the science on Hubble for its first three years depended on the WF/PC. "It's distressing that the camera works perfectly well, but the mirror is imperfect," says Blair Savage, principal investigator for the HRS. Fortunately, though, a second-generation camera is under construction and is scheduled for a 1993 mission. For now, image reconstruction programs being developed could clean up the pictures. NASA's recently published pictures from HST of 30 Doradus, a stellar nursery, and the galaxy NGC 7457 attest to that, say astronomers. Because of the flaw in the mirror, the other instruments can perform, on average, only half of what they were expected to do. But the two spectrographs are to be replaced with advanced instruments in 1996. And correcting optics could improve their performances, according to principal investigator of the FOS, Richard Harms. Nothing, however, is planned for the photometer, says its principal investigator, Robert Bless of the University of Wisconsin, Madison, nor for the FOC, which was built by the European Space Agency (ESA) at a cost of $100 million. The Europeans have no plans for a second-generation replacement; according to an article in Physics Today (August 1990), some scientists at ESA, angry at shuttle delays that have cost the agency about $70 million, believe NASA should provide them with a new one. --R.E. The full extent of the devastation caused by the spherical aberration in the primary mirror, an effect that limits the amount of light capable of being focused toward five of the telescope's six instruments--two cameras, two spectrographs, and a photometer--will not be known for many weeks, until NASA completes tests of the telescope (see accompanying story). Yet astronomers have already begun to identify which projects are still workable, which must be delayed until second-generation instruments with correcting optics are shuttled up, and which projects must be scrapped. For example, programs that require observations of faint objects at the edge of the galaxy, which could answer cosmological questions such as the evolution of galaxies, are among those that can no longer be done, says Edward Weiler, Hubble Space Telescope (HST) program scientist at NASA. But for the telescope that is orbiting the earth every 96 minutes, the star show must go on. As part of the reassessment process, astronomers are scrambling to submit revised research proposals and protocols for a new round of peer review. During the first round of review, astronomers, often working as part of a team, pored through books the size of phone directories outlining the capabilities of the telescope and through handbooks describing each of the six instruments. After doing computer simulations of their projects to determine if they were feasible, they submitted their proposals for review by two committees. Now the process begins again. Because data that would allow astronomers to make accurate changes to their research plans aren't available yet, scientists must make educated guesses in order to get their proposals in on time. "In order to have programs run on the telescope in January or February we need changes by Christmas but we can't tell them exactly what they need to know yet in order to change them," says Bruce Gillespie, head of the Users Group at STSI, which is under contract with NASA to coordinate observers and Goddard astronomers who do the actual programming of the telescope. Rescuing an original Hubble program in many instances will mean increasing the exposure time during an observation to compensate for the decreased light available to the instruments. "I have to live with a factor of five-fold less efficiency," says Blair Savage, principal investigator for the high-resolution spectrograph, who works out of the University of Wisconsin, Madison. This effectively reduces by 80 percent the number of observations he can perform in his 350 hours of allotted time. It is unlikely NASA will give him and others more time, but they are considering it, says Gillespie. Savage's and the other 80 teams of guaranteed-time observers-- those astronomers who participated in the design and building of the instruments since the 1970s--must have their projects ready for a NASA committee review by November. The 140 teams of general observers (GOs), those astronomers who applied for and received observation time on the telescope, will also be reviewed by STSI during November. Deadlines for submissions of proposals for the second year of Hubble's orbit have been delayed until February 15 from November 15. For Carleton Pryor, assistant professor of physics and astronomy at Rutgers University in New Brunswick, N.J., one positive note about the Hubble situation is that he won't be going through the proposal process this year. "The joke when the last application process was going on, was that all advances in astronomy stopped for those five or six months," he says. His team is asking for a deferral of their time until the second-generation camera is shuttled up to the telescope in 1993. The extant camera cannot provide the necessary resolution to observe faint stars in globular clusters, part of his team's work. After the re-examination process, NASA will be able to sort out the $8.5 million in funding allocations for the first-year observers. Money will be redistributed according to how much time astronomers use on the telescope. "Many guaranteed-time observers are currently getting money [as part of their NASA contracts to work on the instruments], but some of their funds may be renegotiated depending on how much time they actually use on the telescope," says NASA program chief Weiler. But for general observers, funding is completely uncertain. Had there been no flaw, GOs would have gotten money after receiving their data from the telescope. So although they are expecting money, after the second review process, they may not get what they counted on. Scientists are also concerned that they will require even more funding to do the additional analysis of the data needed because of the mirror defect. "The hardest hit economically are those astronomers at the assistant and associate professor level in universities on tenure tracks, who relied on this money for beefing up their research to buy computers and pay for postdocs and graduate students," says STSI astronomer Robert Griffiths. Besides forcing astronomers to do additional testing of the Hubble telescope, the setback in the highly publicized program has tested the tolerance of the astronomy community in withstanding a strange mix of public ridicule and pity. While most are terribly disappointed, they also remain philosophical. "A scientist, when he walks into the lab, takes his life into his hands," says 74-year-old Johns Hopkins astrophysicist William Fastie, who has worked on the wide-field/planetary camera for the last 20 years and now is trying to ensure that his students will take up where he will leave off because of his advanced age. "A project doesn't always work or someone beats you to it. There are so many hazards when you decide to be a scientist. But you must buy those hazards. "If you miss, you can always apply the experience somewhere later on in your career. If you're discouraged and leave the field, that is your decision. If you do a risky project it can pay off or you could wind up empty-handed. But a safe project could also give you nothing." Blair Savage, the principal investigator for the high-resolution spectrograph from the University of Wisconsin, is trying to resolve who is responsible for the defect. "I don't like to get into the blame mode but in trying to prevent this from happening again, it requires knowing how it happened, and where the system went wrong," he says."At some level, a bit of blame could be shared by everybody, not just the industrial outfits and NASA, but the scientists themselves. More astronomers could have been involved, although it is not easy to do when you have such a formidable bureaucracy." Hubble Space Telescope program director Edward Weiler reflects: "Of course I am disappointed. We can all sit back and say we tried something hard and we had early failures and quit or we can say we tried something hard and the American spirit is to keep trying. What worries me is what kind of message we are sending to our children. I have no problem with negative press if it is correct. But it tends to report the half-empty side of the story. The first day, when we announced the flaw, I said, `I would be lying if I said that we weren't frustrated, but no one is walking away form the program.' Many reports printed only the part up to `frustrated.' " For veteran astronomer Susan Simkin of Michigan State University, the struggle to get answers from the bureaucracy about the flaw is reaffirming her fighting spirit. "I'm in my fifties, and extremely aggressive and know most of the senior people," she says. "Face to face, I can make them back down. If I was younger and didn't have as much knowledge about physics and astronomy, I'd be scared. Fighting is an important part of my lifestyle." --R.E. Rogier Windhorst, assistant professor of physics and astronomy at Arizona State University, Tempe, keeps telling his programmer and two graduate students to sit tight, hoping that the money to pay for them will come through by next year. "I was able to scrounge up some teaching assistant money for the students from the university," he says. "With the HST money they would have only to do research." Without the HST money, he's afraid he'll lose them to other departments that wouldn't require them to teach. Griffiths' is another case of a scientist whose team is deferring much of its work until a new camera is on board--but with far-reaching implications. Griffiths' 200 hours on HST involved doing serendipitous observing--taking random pictures with the camera when other instruments were being used. To do this he had to develop computer programs. Other scientists relied on his writing these programs because they, too, had projects involving serendipitous programming. "At present we don't know when [the programs] would be realistically available," he says. Fortunately, most HST astronomers' projects didn't rely on others' results, nor did most Hubble astronomers rely on their HST proposals for all their funding or research. To change his graduate student's project from HST to a German X-ray satellite, all Griffiths had to do was make a phone call. Other Hubble astronomers work in ground-based observatories, or on other astrophysical projects. "While many would have preferred to work on Hubble, they are not going to sit around and do nothing," says spectrograph investigator Savage. But for William Fastie, a professor of astronomy at Johns Hopkins University in Baltimore, the Hubble's problem is particularly disappointing. Fastie, 74, got involved in building the telescope more than a decade ago, expecting to use the high-resolution camera in the mid-1980s to look for companions to nearby stars. By the time NASA fixes the camera in 1993, he says, "I won't be doing this anymore." For the most part, there is guarded optimism among the star-gazers. Michigan State University physics and astronomy professor Susan Simkin can no longer get the quantitative information from Hubble on the formation of galaxies for which she was hoping, but she is hanging tough to her 12« hours of observation time. Simkin hopes that even though she'll be doing fewer observations than planned, she'll get some clue as to how materials are fed into black holes at the centers of active galaxies. "I came to Goddard this summer to learn computer programming for my HST project," says Simkin, "but got stuck in workshops on what was wrong with the telescope. That's fine. It's better for me to be here and know what's really going on than to rely on the rumor mill or electronic mail."

The Hubble Problem: Scientists Try To Pick Up The Pieces

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