The "first light" image from the Hubble telescope was almost universally hailed as the beginning of a new era in astronomy and cosmology. Upon closer scrutiny, however, a team of experts discovered that the photograph-which showed a star cluster over 1,300 light years distant-was poorly focused, a smudged halo of light rather than the tight image they had expected. The result was a first-order public relations disaster: once the darling of science journalists, the Hubble telescope came to embody everything wrong with the federal government's "big science" projects. Critics charged that not only were these massively expensive ventures available mainly to narrow scientific communities but they were a bad investment: the technology was so complex that failures, sometimes catastrophic, were statistically inevita-ble. The general feeling was that perhaps it was time to return to projects designed for small laboratory settings.

But in Hubble Vision, science journalist Carolyn C. Peterson and astronomer John C. Brandt affirm that investment in the Hubble telescope was indeed justified. Granted, the telescope is a dauntingly intricate machine. The authors admit that virtually every major system is operating under some flaw that limits its performance, or, in a few cases, renders multi-million-dollar devices inoperable. The star-cluster image that occasioned such praise and, later, such approbation came by its imperfections through normal wear: a tiny speck of paint that chipped off the cap of a testing device caused a light leak-and hence a crucial mirror was ground with an error of about a micron, or one-millionth of a meter. A flapping solar panel that jiggled the telescope smeared still other images. Moreover, software problems continue to surface, such as the ones that have affected the "fine guidance sensors," which have sometimes focused the telescope on the wrong target. Yet because of the unique capabilities of the telescope's many instruments, the authors point out, we are witnessing advances in virtually every aspect of astronomy, astrophysics, and cosmology.

Since the Hubble operates in space, where the filtering effects of earth's atmosphere are not a problem, its "Goddard high-resolution spectrograph," or GHRS, can zero in on ultraviolet radiation emissions in unprecedented detail. And through spectroscopy-a technique that breaks down those emissions into their component wavelengths-research-ers can begin to understand the life cycles of heavenly bodies. The reason is that different wavelengths are associated with specific chemical elements, which we know to behave in predictable ways. Beta Pictoris, a star surrounded by elements that appear to be coalescing into planets, is one of hundreds of subjects being studied. Observations of the various elements falling into its core, as well as those forming orbits around it, have enabled astrophysicists to record the stages of a star system's development for the first time. GHRS can even determine the chemical composition of precise regions within Beta Pictoris.

The telescope could also challenge a pivotal notion of its namesake, Edwin Hubble, as astronomers attempt to more accurately define the "Hubble constant"-that is, the rate at which galaxies are receding from one another.  Because of its vantage point in space, where, again, there is no atmosphere to complicate matters, the Hubble telescope can greatly refine techniques for measuring galactic distances, and if the refinements turn out to be significant, it would mean that galaxies are receding from one another faster or more slowly than Hubble had thought. And that, in turn, could mean a change in our notion of the age of the universe: a faster rate suggests a younger universe, a slower rate an older one.