A New Addition to the International Space Station

On its final cosmic journey before retirement in May 2011, the shuttle Endeavour delivered a precious payload to the International Space Station. The cargo was a $2 billion scientific instrument that had been in the works for more than 15 years: the Alpha Magnetic Spectrometer (AMS), designed to detect and sort hundreds of billions of high-energy charged particles whizzing through space.

One goal of the dizzying data collection is to understand why matter and antimatter, believed to have been created in equal measure when the universe was born, didn’t annihilate themselves out of existence. If they had, there would be no matter as we know it: no stars, no planets, no gelato. To look for lingering anti­matter, AMS contains a giant doughnut-shaped magnet that creates a magnetic field 3,000 times as strong as Earth’s. Subatomic particles streaming through the device bend according to their charge; detectors collect details on a particle’s path and speed, beaming these and other stats back to Earth.

Championed by the Nobel Prize-winning physicist Samuel Ting of MIT, the instrument, which weighs more than three Hummer H3s, almost didn’t make it off the ground. The Columbia shuttle disaster in 2003 left its future uncertain, but Ting managed to keep it alive. Scientists are still working through early data: “You have to check your results very carefully,” Ting says. But expect initial findings to be announced any minute now.