RENEE MONTAGNE, host:
The Space Shuttle Endeavor is scheduled to blast off this afternoon on its final mission. President Obama will be there for the launch. So will Congresswoman Gabrielle Giffords. In January, she survived an attack where she was shot in the head, but has recovered enough to watch her astronaut husband go into space.
The launch will also be watched by physicists. That's because Endeavour will be carrying up an expensive and controversial physics experiment. NPR's Nell Greenfieldboyce reports that it will look for strange forms of matter.
NELL GREENFIELDBOYCE: The instrument is the Alpha Magnetic Spectrometer, or AMS. A few years ago, physicist Drew Baden of the University of Maryland got to see it as it was being assembled. He says it was the size of a bus and looked a bit like the old Sputnik satellite.
Professor DREW BADEN (Physicist, University of Maryland): It's got sort of a cylindrical geometry. And it's got legs. And it's all shiny and, you know, silvery.
GREENFIELDBOYCE: Its high-tech innards are a big magnet and detectors to measure cosmic rays. These are charged particles that zoom through space. The AMS will sift through them, looking for strange things like primordial antimatter created during the Big Bang, and the mysterious dark matter thought to make up much of our universe.
To Baden, the instrument was gorgeous.
Prof. BADEN: It was just beautiful, beautiful. I thought it was beautiful. Just thinking about the engineering that went into it and the amount of time it took and the planning - wow. I mean, that human beings could accomplish this kind of thing is really impressive.
GREENFIELDBOYCE: One human being in particular was a Nobel Prize winning physicist named Sam Ting, of the Massachusetts Institute of Technology. For more than 16 years, he's been the driving force behind this project, leading hundreds of researchers in more than a dozen countries.
Ting never gave up, not even in the wake of the Space Shuttle Columbia disaster when NASA officials went back on their promise to take the AMS up into space. Ting lobbied relentlessly until the mission got reinstated. At a press conference yesterday, Ting said no one knows what the AMS might discover.
Dr. SAM TING (Massachusetts Institute of Technology): To a scientist the most exciting objective of AMS is to probe the unknown, to search for phenomena which exist in nature that we have not yet imagined nor have the tool to discover.
GREENFIELDBOYCE: But some physicists are not expecting any breakthroughs.
Professor GREGORY TARLE (Physics, University of Michigan): I just think that this experiment was a tremendous expenditure of money that wasn't justified.
GREENFIELDBOYCE: Gregory Tarle is a physics professor at the University of Michigan. He says the AMS cost an estimated $2 billion, but went forward without first getting widespread support from the physics community. He says its original purpose was to find primordial anti-matter, but more recent research shows there's no way it will find any.
Prof. TARLE: The justification for doing this kind of physics has pretty much evaporated.
GREENFIELDBOYCE: And while it will look for evidence of dark matter, Tarle says, its results won't be conclusive.
Despite the controversy, physicists say they are interested in seeing what the AMS will do. Sheldon Glashow is a Nobel Prize winning physicist at Boston University. He says it's a powerful instrument.
Dr. SHELDON GLASHOW (Physicist, Boston University): Let's put it up into the sky. I think it would be absolutely catastrophically stupid to not put it up in the sky. It will finally be true that there will be real science on the space station, something that has never been true before - it's been like high school experiments and a bunch of silliness.
GREENFIELDBOYCE: After Endeavour gets to the space station, astronauts will use robotic arms to attach the AMS to the orbiting lab, where it will stay for a decade or more, taking in the cosmic rays.
Nell Greenfieldboyce,�NPR News.
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