Positive Charge for Rosetta Detecting ions, or charged particles from either solar wind or comet tails, is one goal for the comet-chasing space probe, Rosetta.    Astrobiology Magazine -- The Ion and Electron Spectrometer (IES), one of three NASA instruments aboard the European Space Agency (ESA) Rosetta comet orbiter, successfully underwent an intensive commissioning exercise that qualified it for operation during the next decade...