In this month's issue of the Journal of Mass Spectrometry, John F. J. Todd and colleagues describe the development of an ion trap for a miniature GC/MS system for space. The system is designed for isotope ratio analysis that will be conducted over the course of the European Space Agency's Rosetta mission to launch a probe to study a comet's nucleus. According to the ESA web site, the Rosetta spacecraft -- "on which all subsystems and payload equipment are mounted" -- is scheduled to meet up with the Churyumov-Gerasimenko comet in May 2014.