The Device NASA Is Leaving Behind

Despite the strong possibility that the instrument will never be used, NASA continues to contribute to its assembly, which is being completed in Geneva. The agency will have spent $75 million on the project by the time it is finished and shipped to the Kennedy Space Center late next year, said NASA project manager Mark Sistilli.

"We're always looking for ways to get it up to the station," Sistilli said. "But given our constraints now with the shuttle program, the agency is in a real quandary."

The AMS is an automated device with a specific set of scientific tasks. The Columbus lab scheduled to be launched next week is a more like a "shirtsleeves" lab that includes specially designed work areas for a wide range of experiments.

Many of the 16 racks in the 23-foot-long lab have experiments in place -- to study the effect of weightlessness on the root systems of plants, the dynamics of fluids in space, how crystals grow without gravity and other questions. Zell, at the European Space Agency, said scientists once thought they could perfect and mass-produce metals in space, but that is no longer considered feasible. But the zero-gravity experiments can teach researchers how to make better metals, or crystals, on Earth, he said.

Columbus will not be the first science lab at the space station; the American Destiny lab was flown to the station in 2001. But scientific experimentation has been limited, in part because the small crew spends most of its time keeping systems running properly, and because the U.S. science mission on the station formally changed in 2005 after Bush announced his exploration initiative.

American science on the orbiting facility is now dominated by research into how months or years in space will affect the human body and what can be done to limit the health effects.

One study of salmonella bacteria in space was recently published in the Proceedings of the National Academy of Sciences and drew significant attention. Researchers from Arizona State University sent the salmonella on a 2006 shuttle mission and found that the bacteria became far more virulent while in space. The scientists later identified a protein involved in the change -- research that may help in space missions while yielding clues on how to better treat and contain salmonella on Earth.

The Columbus lab will get relatively limited crew time, at least until 2009, when the crew size is to increase from three to six. According to Zell, the experiments on Columbus range from those that are largely mechanical and computerized to life science and crystal experiments that require frequent human involvement. The lab, designed to last 10 years in orbit, will have several small, unpressurized pods that will expose bacteria and metals to the radiation, vacuum and extreme temperatures of space; another will monitor and measure solar radiation.

Nobel laureate Steven Weinberg, a theoretical physicist at the University of Texas, is one of many researchers frustrated by the priorities NASA has set, and he has publicly discussed the AMS issue as a prime example of what he thinks has gone wrong. If the instrument were ferried to the station, he said, its study of cosmic rays "would be the only significant science ever done on the space station."

"This device could make discoveries that are Earth-shattering," he said. "We have an opportunity now to do some worthwhile fundamental science on the ISS, and they're resolutely turning their back on it."

For more information on the Columbus laboratory, go tohttp://www.esa.int/SPECIALS/Columbus/SEMURE63R8F_0.html.