Gas Chromatography in Space ExplorationReference Module in Chemistry, Molecular Sciences and Chemical Engineering

Gas chromatography (GC) instruments have been successfully installed on the spatial probes for in situ chemical analyses of planetary atmospheres or surfaces, for searching for chemical biomarkers that could provide evidence of extinct or extant life in space. GC instruments and analytical procedures have been developed in order to meet the severe requirements imposed by flight conditions: short analysis time and low energy consumption, robustness, high efficiency and sensitivity, automation, and remote control operations. The instrument payloads include devices that provide different sample handling and pretreatment prior to GC analysis, such as pyrolysis for thermal volatilization of volatiles or solvent extraction of polar organic compounds. This article describes three recent space missions: Cassini–Huygens to Titan, Rosetta to comet 67P/Churyumov–Gerasimenko, and the Mars space exploration program. The technical data of the onboard GC instruments are given; the results provided by in situ GC analyses are discussed to give information on the chemical composition of the extraterrestrial atmospheres and soils.