Even Telescope’s Downtime Is Booked : Research: An astro- physicist’s idea to get random views of space as the Hubble is moved stirs envy among his colleagues.

Despite years of planning, significant chunks of precious observation time on the space telescope deployed on Wednesday nearly went unused because, until the 11th hour, no one had thought to take advantage of the telescope’s downtime as it switched from one task to another.

But when astrophysicist John N. Bahcall finally came up with a productive use for that time, he unwittingly stirred up a hornet’s nest of envy that also illuminated the high stakes involved.

What Bahcall came to recognize was the rare chance to take random “snapshots” of the cosmos during the unscheduled minutes while the $1.5-billion telescope is being repositioned for each of the hundreds of meticulously planned observations during its early years. Each such window of opportunity could last four to five minutes, although that may diminish over the years as operators become more proficient at maneuvering the 12-ton instrument, officials say.

Riccardo Giacconi, director of the NASA-affiliated Space Telescope Science Institute in Baltimore, Md., loved Bahcall’s idea and, exercising a telescope director’s traditional prerogative, he readily gave Bahcall that time.

But that riled many astronomers who believed that the time-honored competitive process had been bypassed--even though Bahcall said from the start that he would make the “snapshots” accessible to all as soon as they became available.

The flap in part is a reflection of the unprecedented, worldwide competition for time on the telescope.

For the initial phase of general observation, for instance, more than 1,500 astronomers from 30 countries submitted 556 proposals seeking 10,700 hours of time. Officials accepted 162 proposals and granted 1,640 hours.

The furor over Bahcall’s minutes has prompted NASA to announce that future time to make random observations also will be subject to open competition. The agency is about to invite applications for the next phase of telescope observation time.

There has always been intense rivalry for access to big-ticket science items, such as the giant particle accelerator outside Geneva, Switzerland, noted D. Allan Bromley, adviser to President Bush for science and technology.

“And it’s a demonstrable fact that, when you have a completely new tool,” he said, “the probability of coming up with something completely new and exciting is obviously much greater.”

Indeed, astronomers have never experienced such fierce competition. And for good reason.

By orbiting high above the Earth’s distorting atmosphere, the space telescope will allow objects to be seen with 10 times greater clarity than with the strongest ground-based telescope. It will enable humans to see close to the edge of the universe.

Thus, winning observation time can well make a career. “No question about it,” said Nolan R. Walborn, acting director of the science program selection office at the space institute.

“It’s almost a guarantee of research success and career success,” said Bahcall, president-elect of the American Astronomical Society and a researcher at Princeton’s Institute for Advanced Study. “Anyone who gets time--especially in the early periods--most likely will make an important contribution to astronomy.”

The telescope has a 15-year life expectancy, but there is a largely unspoken fear among many that it might suffer a fatal blow from a meteor or one of nearly 6,000 pieces of space debris.

“It was always in the back of your mind: What if disaster hits after the first year?” said University of Maryland astronomer Roger A. Bell, who chaired one of the project’s time allocation committees.

Such fears, he said, may help explain the particularly keen competition for time early in the telescope’s life.

The first eight months in orbit are devoted primarily to testing and calibrating the telescope’s vast array of delicate instruments. But “guaranteed-time observers,” the term NASA uses for scientists like Bahcall, will be allowed to begin their observations during this phase.