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Have we got gravity all wrong?

03 June 2006

Stuart Clark

Magazine issue 2554

Virtual replays of two of the most puzzling space missions ever undertaken – the Pioneer 10 and 11 probes - could solve the mystery

SLAVA TURYSHEV is a man on a mission. Two missions in fact. The researcher from NASA's Jet Propulsion Laboratory in Pasadena, California, is about to re-fly the two most controversial spacecraft in history. The Pioneer 10 and 11 probes were launched in 1972 and 1973 and are now drifting in deep space beyond the outermost planets of the solar system. NASA lost contact with Pioneer 10 in 2003, but though the probes are now long gone, they are anything but forgotten. That's because Pioneer 10, when last heard from, seemed to be off course by around 400,000 kilometres and nobody has ever been able to figure out why. Did some malfunction nudge the craft off its expected trajectory, or are there deeper forces at work?

Pioneer 10's sister ship is also being pushed off course, and an analysis of the Galileo spacecraft to Jupiter and the Ulysses solar probe hints ...

The complete article is 2338 words long.

http://www.newscientist.com/article/mg19025541.800.html