An instrument for detecting cosmic rays – and possibly even dark matter – has finally been lifted into orbit on board the space shuttle Endeavour. The Alpha Magnetic Spectrometer (AMS), which is the brainchild of the Nobel-prize-winning physicist Samuel Ting, will soon be installed on the International Space Station (ISS). Ting first came up with the idea for the AMS in the 1990s but a series of setbacks, including the Columbia space shuttle disaster in 2003, has led to the mission being continually delayed.
The launch of the AMS also marks the end of an era in space exploration as this is the final mission of NASA’s space shuttle programme – which began with the launch of Columbia in April 1981. The lift-off from Kennedy Space Center in Florida was attended by US President Barack Obama, who led celebrations commemorating the 30-year space shuttle programme.
Costing $2bn and weighing 7 tonnes, the AMS detector uses a 0.15 T cylindrical magnet 1 m in diameter and 1 m in height to sort incoming particles according to their momentum and charge. The direction of bend of the particle tracks through the magnet’s bore depends on whether the particles are matter or antimatter, while the gradient of the bend is determined by their speed. This will allow the detector to distinguish between vast numbers of different types of cosmic-ray particle.