The first unambiguous consequence of the existence of stardust within meteorites came from the laboratory of Edward Anders in Chicago, who found using traditional mass spectrometry that the xenon isotopic abundances contained within an acid-insoluble carbonaceous residue that remained after the meteorite bulk had been dissolved in acids matched almost exactly the predictions for isotopic xenon in red giant stardust. It then seemed certain that stardust grains were contained within Anders' acid-insoluble residue. Finding the actual stardust grains and documenting them was a much harder challenge that required locating the grains and showing that their isotopes matched those within the red-giant star. There followed a decade of intense experimental searching in the attempt to isolate individual grains of those xenon carriers. But what was really needed to discover stardust was a new type of mass spectrometer that could measure the smaller number of atoms in a single grain. Sputtering ion probes were pursued by several laboratories in the attempt to demonstrate such an instrument. But the contemporary ion probes needed to be technologically much better.