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NASA 'Gravity Probe B' Project Winds Down

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NASA 'Gravity Probe B' Project Winds Down


NASA 'Gravity Probe B' Project Winds Down

NASA 'Gravity Probe B' Project Winds Down

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  • <iframe src="" width="100%" height="290" frameborder="0" scrolling="no" title="NPR embedded audio player">
  • Transcript

NASA researchers spent nearly 40 years on Gravity Probe B, a satellite designed to test some of Albert Einstein's theories. As the $700 million project winds down, NASA is rejecting a request for another 18 months of funding.


From NPR News, this is ALL THINGS CONSIDERED. I'm Michele Norris.

NASA has decided to stop funding a satellite experiment designed to test Einstein's theory of relativity. The decision could end the longest project in NASA's history, work it began in 1963. Scientists on the experiment say they need a couple of more years to finish analyzing their data. The space agency says no.

NPR's David Kestenbaum says this...

DAVID KESTENBAUM: The project called the Gravity Probe B was never supposed to take this long. Francis Everitt has been working on it for over four decades. By his count it got cancelled seven times along the way. Each time the team persevered, feeling it was too important to give up on.

Mr. FRANCIS EVERITT (Gravity Probe B, Principal Investigator): Einstein's theory of gravitation, general relativity, is one of the most beautiful theories in physics. We also know this theory is exceedingly difficult to test; there have been really very few tests.

KESTENBAUM: Gravity Probe B was designed to conduct fundamental tests that would measure the subtle bending of space time by Earth's gravity and see if it agreed with Einstein's predictions. The experiment finally launched in 2004; on board were extremely precise gyroscopes. And they worked really well, but not quite as well as designed. They wobbled slightly, threatening to ruin the experiment. The spacecraft is dead now, but Everitt says they have a way to fix the data they've collected. Just one problem, - they need another $2 to $4 million. NASA has already spent over $700 million on the project.

Mr. EVERITT: It would be a very sad event if we had to end here, leaving something unfinished when you're so close.

KESTENBAUM: NASA had a panel of independent scientists review the request. It compared Gravity Probe B, GP-B, to nine other experiments that all wanted more money, and the panel ranked Gravity Probe B dead last.

Mr. MICHAEL SALAMON (Gravity Probe B Program): There were two fundamental reasons why they've ranked GP-B as low they did.

KESTENBAUM: Michael Salamon is NASA's program scientist for the project. The first reason, he says, is the panel felt Gravity Probe B is just too late. The tests of Einstein's theory it wanted to perform have already been done in other ways.

Mr. SALAMON: And therefore, although this is a great idea, and remembered, it was initiated over 40 years ago, time has overtaken the importance of this experiment.

KESTENBAUM: Other panels have given the experiment better reviews, but this one had a second serious concern, which is that the wobbles in the data might be too big to fix convincingly.

Mr. SALAMON: This panel did not believe that they would be able to do this based on the history of the data analysis that's been done thus far.

KESTENBAUM: NASA has already given the experiment additional funding three times to finish the analysis. Salamon says this is a sad day, but budgets are tight; NASA is having trouble funding projects that ranked in the middle of that list, much less the bottom.

Mr. SALAMON: Personally, if there were lots of money around, I would definitely want to continue GP-B. But at this point the agency has decided that we can no longer continue to support Gravity Probe B.

KESTENBAUM: Francis Everitt says when he got the news he felt NASA had made the wrong decision. But the project has had numerous near death experiences, and they've only been near death.

Mr. EVERITT: Oh, GP-B has being hard all along, and we've carried it forward. My favorite American hero, John Paul Jones, in the fight with the British, actually off the coast of England, he was asked if he was going to surrender and he said, I haven't even begun to fight yet. That was when his ship was half shot away. He ended up by winning the battle.

KESTENBAUM: Gravity Probe B may live to fight another day. Everitt says the experiment recently got a gift of $500,000. It came from a man named Richard Fairbank. He's the CEO of Capital One, the giant finance company. Fairbank's father was a physicist who decades ago worked on Gravity Probe B.

David Kestenbaum, NPR News.

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