Given the recent success of LIGO detecting gravitational waves, it shouldn't be surprising there is renewed interest in the press regarding other plans for building gravitational detectors. I found the recent article in Scientific American on the subject interesting...
Test Marks Milestone for Deep-Space Gravitational Wave Observatory
Scientists have long dreamed of launching a constellation of detectors into space to detect gravitational waves - ripples in space-time first predicted by Albert Einstein and observed for the first time earlier this month. That dream is now a step closer to reality. Researchers working on a €400 million (US$440 million) mission to try out the necessary technology in space for the first time-involving firing lasers between metal cubes in freefall - have told Nature that the initial test-drive is performing just as well as they had hoped.
"I think we can now say that the principle has worked," says Paul McNamara, project scientist for the LISA Pathfinder mission, which launched in December. "We believe that we now are in a good shape to look to the future and look to the next generation." "Everything works as we designed it. It's sort of magical and you rarely see that in your career as an experimentalist," says Stefano Vitale, a physicist at the University of Trento in Italy, and a principal investigator for the Pathfinder mission. The European Space Agency financed the test, and hopes ultimately to launch a €1-billion mission to hunt for gravitational waves. That would bounce lasers between three spacecraft, set millions of kilometres apart. Each craft would contain a test mass (a metal cube) which would be placed in freefall, protected from any forces except that of gravity. Because gravitational waves stretch and compress space-time, the observatory hopes to be able to see passing waves by using the lasers to detect minute changes in the distance between the freefalling cubes.
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